causes for lean condition and p0131
07-06-2013, 06:58 PM
#1
TECH Enthusiast
Thread Starter
causes for lean condition and p0131 hey guys long story short i did a tsp v3 cam, ls6 intake bosch 40# injectors and prc 2.5 heads on my 2000 z28, i pulled two codes after the swap p0131 and p0300 , i went to new era performance to have it tuned and mike said that i had a massive vacuum leak mostly on the drivers side, so i pulled the intake and inspected it and found nothing wrong with the intake i had even bought new gaskets. i pulled the plugs on the drivers side and they were all white at the top on each of them, passenger side was normal. i tried putting the ls1 intake back on and STILL had the same issues so i put the ls6 back on and tried spraying carb cleaner around the intake and found no leaks even tried on the pcv lines and no change in rpm. the car bogs bad when i first give it gas then picks up immediatly, when im cruising you can hear the rpms fluctuating back and fourth, at this point im at a complete loss and the car has been sitting since the beginning of june im in need of SERIOUS help and ideas at this point this is where im at on what is causing my issues:
-possibly all four injectors on drivers side bad?
-spark plugs fouled
-bad fuel filter
-some sort of intake leak
-bad oxygen sensor?
-possibly all four injectors on drivers side bad?
-spark plugs fouled
-bad fuel filter
-some sort of intake leak
-bad oxygen sensor?
07-12-2013, 01:40 AM
#6
TECH Enthusiast
Thread Starter
Trending Topics
07-14-2013, 07:29 PM
#8
Document ID# 791149
Chevrolet Camaro
DTC P0131 or P0151
Circuit Description
The powertrain control module (PCM) supplies a voltage of about 450 mV between the heated oxygen sensor (HO2S) high and low signal circuits. The oxygen sensor (O2) varies the voltage from approximately 1,000 mV when the exhaust is rich, through approximately 10 mV when the exhaust is lean.
The PCM monitors and stores the HO2S voltage information. The PCM evaluates the HO2S voltage samples in order to determine the amount of time the HO2S voltage was out of range. The PCM compares the stored HO2S voltage samples taken within each sample period, and determines if the majority of the samples are out of the operating range.
The PCM monitors the HO2S voltage for being fixed below a predetermined voltage. If the PCM detects the voltage is below a predetermined voltage, a DTC sets.
Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0200, P0300 P0410, P0440, P0442, P0446, P0452, P0453, P1258, P1415, P1416, or P1441 are not set.
The ignition 1 signal is between 9-18 volts.
The fuel tank level remaining is more than 10 percent.
The loop status is closed.
Intrusive tests are not in progress.
Scan tool output controls are not active.
Lean Test Enable
The air fuel ratio is between 14.5:1 and 14.7:1.
The throttle position (TP) is between 3-70 percent.
Power Enrichment Test Enable
Power enrichment is active.
The above condition is met for 1 second.
Conditions for Setting the DTC
Lean Test
The HO2S voltage is less than 200 mV for 165 seconds.
Power Enrichment Test
The HO2S voltage is less than 360 mV for 10 seconds.
Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
The control module commands Open Loop.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
Important
Before you service the PCM, remove any debris from the PCM connector surfaces. Inspect the PCM connector gaskets when you diagnose or replace the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the PCM.
For any test that requires probing the PCM or component harness connectors, use the J 35616-A Connector Test Adapter Kit . Using this kit prevents any damage to the harness connector terminals. Refer to Using Connector Test Adapters in Wiring Systems.
The PCM sets this DTC when the vehicle runs out of fuel. Inspect for the following conditions:
The heated oxygen sensor (HO2S) wires--The sensor pigtail may be in contact with the exhaust manifold or the exhaust system.
The oxygen supply--An oxygen supply inside the HO2S is necessary for proper operation. The HO2S wires provide the supply of oxygen. Inspect the HO2S wires and connections for breaks or for contamination. Refer to Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems.
An intermittent ground--Inspect for an intermittent ground in the signal wire between the connector and the sensor.
Lean injectors--Perform the Injector Balance Test. Refer to Fuel Injector Balance Test with Tech 2 or Fuel Injector Balance Test with Special Tool .
Fuel contamination--Water near the in-tank fuel pump inlet can be delivered to the injectors. Refer to Alcohol/Contaminants-in-Fuel Diagnosis . The water causes a lean exhaust and can set a DTC.
The fuel pressure--If the fuel pressure is too low, the system will be lean. Refer to Fuel System Diagnosis .
Exhaust leaks--An exhaust leak near the HO2S can cause a lean condition. Refer to Exhaust Leakage in Engine Exhaust.
Vacuum or crankcase leaks can cause a lean condition.
If the above components are OK, the HO2S may be at fault.
For an intermittent condition, refer to Symptoms - Engine Controls .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
If the voltage is below the specified value, the condition is present.
A disconnected sensor should indicate a bias voltage. If the voltage is low, inspect the signal circuit for a short to ground.
Step
Action
Values
Yes
No
Schematic Reference: Engine Controls Schematics
1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls
2
Start and run the engine until normal operating temperature is reached.
With a scan tool, observe the HO2S voltage for the sensor that applies to this DTC.
Is the HO2S voltage less than the specified value?
200 mV
Go to Step 4
Go to Step 3
3
Observe the Freeze Frame/Failure Records data for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or as close to the Freeze Frame/Failure Records data that you observed.
Does the DTC fail this ignition?
--
Go to Step 4
Go to Diagnostic Aids
4
Turn OFF the ignition.
Disconnect the HO2S connector for the sensor that applies to this DTC.
Jumper the HO2S low signal circuit terminal on the engine harness side to a known good ground.
Turn ON the ignition, with the engine OFF.
Use a scan tool in order to observe the HO2S voltage.
Is the HO2S voltage within the specified range?
350-550 mV
Go to Step 5
Go to Step 6
5
The HO2S may be detecting a lean exhaust condition. Inspect for the following conditions:
Water intrusion into the HO2S connector
Exhaust leak between the HO2S and the engine
Vacuum leaks
Incorrect fuel pressure
Lean fuel injectors
Inaccurate MAF sensor
Repair any of the above or similar engine conditions as necessary.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 8
6
Turn OFF the ignition.
Disconnect the PCM connector that contains the HO2S high signal circuit. Refer to Powertrain Control Module (PCM) Replacement .
Test the HO2S high signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 7
7
Test the HO2S high signal circuit for a short to the HO2S Low signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 9
8
Inspect for poor connections at the harness connector of the HO2S. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 10
9
Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 11
10
Replace the affected HO2S. Refer to Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1 or Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1 .
Did you complete the replacement?
--
Go to Step 12
Chevrolet Camaro
DTC P0131 or P0151
Circuit Description
The powertrain control module (PCM) supplies a voltage of about 450 mV between the heated oxygen sensor (HO2S) high and low signal circuits. The oxygen sensor (O2) varies the voltage from approximately 1,000 mV when the exhaust is rich, through approximately 10 mV when the exhaust is lean.
The PCM monitors and stores the HO2S voltage information. The PCM evaluates the HO2S voltage samples in order to determine the amount of time the HO2S voltage was out of range. The PCM compares the stored HO2S voltage samples taken within each sample period, and determines if the majority of the samples are out of the operating range.
The PCM monitors the HO2S voltage for being fixed below a predetermined voltage. If the PCM detects the voltage is below a predetermined voltage, a DTC sets.
Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0200, P0300 P0410, P0440, P0442, P0446, P0452, P0453, P1258, P1415, P1416, or P1441 are not set.
The ignition 1 signal is between 9-18 volts.
The fuel tank level remaining is more than 10 percent.
The loop status is closed.
Intrusive tests are not in progress.
Scan tool output controls are not active.
Lean Test Enable
The air fuel ratio is between 14.5:1 and 14.7:1.
The throttle position (TP) is between 3-70 percent.
Power Enrichment Test Enable
Power enrichment is active.
The above condition is met for 1 second.
Conditions for Setting the DTC
Lean Test
The HO2S voltage is less than 200 mV for 165 seconds.
Power Enrichment Test
The HO2S voltage is less than 360 mV for 10 seconds.
Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
The control module commands Open Loop.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
Important
Before you service the PCM, remove any debris from the PCM connector surfaces. Inspect the PCM connector gaskets when you diagnose or replace the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the PCM.
For any test that requires probing the PCM or component harness connectors, use the J 35616-A Connector Test Adapter Kit . Using this kit prevents any damage to the harness connector terminals. Refer to Using Connector Test Adapters in Wiring Systems.
The PCM sets this DTC when the vehicle runs out of fuel. Inspect for the following conditions:
The heated oxygen sensor (HO2S) wires--The sensor pigtail may be in contact with the exhaust manifold or the exhaust system.
The oxygen supply--An oxygen supply inside the HO2S is necessary for proper operation. The HO2S wires provide the supply of oxygen. Inspect the HO2S wires and connections for breaks or for contamination. Refer to Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems.
An intermittent ground--Inspect for an intermittent ground in the signal wire between the connector and the sensor.
Lean injectors--Perform the Injector Balance Test. Refer to Fuel Injector Balance Test with Tech 2 or Fuel Injector Balance Test with Special Tool .
Fuel contamination--Water near the in-tank fuel pump inlet can be delivered to the injectors. Refer to Alcohol/Contaminants-in-Fuel Diagnosis . The water causes a lean exhaust and can set a DTC.
The fuel pressure--If the fuel pressure is too low, the system will be lean. Refer to Fuel System Diagnosis .
Exhaust leaks--An exhaust leak near the HO2S can cause a lean condition. Refer to Exhaust Leakage in Engine Exhaust.
Vacuum or crankcase leaks can cause a lean condition.
If the above components are OK, the HO2S may be at fault.
For an intermittent condition, refer to Symptoms - Engine Controls .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
If the voltage is below the specified value, the condition is present.
A disconnected sensor should indicate a bias voltage. If the voltage is low, inspect the signal circuit for a short to ground.
Step
Action
Values
Yes
No
Schematic Reference: Engine Controls Schematics
1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls
2
Start and run the engine until normal operating temperature is reached.
With a scan tool, observe the HO2S voltage for the sensor that applies to this DTC.
Is the HO2S voltage less than the specified value?
200 mV
Go to Step 4
Go to Step 3
3
Observe the Freeze Frame/Failure Records data for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or as close to the Freeze Frame/Failure Records data that you observed.
Does the DTC fail this ignition?
--
Go to Step 4
Go to Diagnostic Aids
4
Turn OFF the ignition.
Disconnect the HO2S connector for the sensor that applies to this DTC.
Jumper the HO2S low signal circuit terminal on the engine harness side to a known good ground.
Turn ON the ignition, with the engine OFF.
Use a scan tool in order to observe the HO2S voltage.
Is the HO2S voltage within the specified range?
350-550 mV
Go to Step 5
Go to Step 6
5
The HO2S may be detecting a lean exhaust condition. Inspect for the following conditions:
Water intrusion into the HO2S connector
Exhaust leak between the HO2S and the engine
Vacuum leaks
Incorrect fuel pressure
Lean fuel injectors
Inaccurate MAF sensor
Repair any of the above or similar engine conditions as necessary.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 8
6
Turn OFF the ignition.
Disconnect the PCM connector that contains the HO2S high signal circuit. Refer to Powertrain Control Module (PCM) Replacement .
Test the HO2S high signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 7
7
Test the HO2S high signal circuit for a short to the HO2S Low signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 9
8
Inspect for poor connections at the harness connector of the HO2S. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 10
9
Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 11
10
Replace the affected HO2S. Refer to Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1 or Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1 .
Did you complete the replacement?
--
Go to Step 12
07-14-2013, 07:30 PM
#9
[continued]
--
11
Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .
Did you complete the replacement?
--
Go to Step 12
--
12
Use the scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run and pass?
--
Go to Step 13
Go to Step 2
13
With a scan tool, observe the stored information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK
Document ID# 791149
Document ID# 791149
2002 Chevrolet Camaro
DTC P0131 or P0151
Circuit Description
The powertrain control module (PCM) supplies a voltage of about 450 mV between the heated oxygen sensor (HO2S) high and low signal circuits. The oxygen sensor (O2) varies the voltage from approximately 1,000 mV when the exhaust is rich, through approximately 10 mV when the exhaust is lean.
The PCM monitors and stores the HO2S voltage information. The PCM evaluates the HO2S voltage samples in order to determine the amount of time the HO2S voltage was out of range. The PCM compares the stored HO2S voltage samples taken within each sample period, and determines if the majority of the samples are out of the operating range.
The PCM monitors the HO2S voltage for being fixed below a predetermined voltage. If the PCM detects the voltage is below a predetermined voltage, a DTC sets.
Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0200, P0300 P0410, P0440, P0442, P0446, P0452, P0453, P1258, P1415, P1416, or P1441 are not set.
The ignition 1 signal is between 9-18 volts.
The fuel tank level remaining is more than 10 percent.
The loop status is closed.
Intrusive tests are not in progress.
Scan tool output controls are not active.
Lean Test Enable
The air fuel ratio is between 14.5:1 and 14.7:1.
The throttle position (TP) is between 3-70 percent.
Power Enrichment Test Enable
Power enrichment is active.
The above condition is met for 1 second.
Conditions for Setting the DTC
Lean Test
The HO2S voltage is less than 200 mV for 165 seconds.
Power Enrichment Test
The HO2S voltage is less than 360 mV for 10 seconds.
Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
The control module commands Open Loop.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
Important
Before you service the PCM, remove any debris from the PCM connector surfaces. Inspect the PCM connector gaskets when you diagnose or replace the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the PCM.
For any test that requires probing the PCM or component harness connectors, use the J 35616-A Connector Test Adapter Kit . Using this kit prevents any damage to the harness connector terminals. Refer to Using Connector Test Adapters in Wiring Systems.
The PCM sets this DTC when the vehicle runs out of fuel. Inspect for the following conditions:
The heated oxygen sensor (HO2S) wires--The sensor pigtail may be in contact with the exhaust manifold or the exhaust system.
The oxygen supply--An oxygen supply inside the HO2S is necessary for proper operation. The HO2S wires provide the supply of oxygen. Inspect the HO2S wires and connections for breaks or for contamination. Refer to Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems.
An intermittent ground--Inspect for an intermittent ground in the signal wire between the connector and the sensor.
Lean injectors--Perform the Injector Balance Test. Refer to Fuel Injector Balance Test with Tech 2 or Fuel Injector Balance Test with Special Tool .
Fuel contamination--Water near the in-tank fuel pump inlet can be delivered to the injectors. Refer to Alcohol/Contaminants-in-Fuel Diagnosis . The water causes a lean exhaust and can set a DTC.
The fuel pressure--If the fuel pressure is too low, the system will be lean. Refer to Fuel System Diagnosis .
Exhaust leaks--An exhaust leak near the HO2S can cause a lean condition. Refer to Exhaust Leakage in Engine Exhaust.
Vacuum or crankcase leaks can cause a lean condition.
If the above components are OK, the HO2S may be at fault.
For an intermittent condition, refer to Symptoms - Engine Controls .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
If the voltage is below the specified value, the condition is present.
A disconnected sensor should indicate a bias voltage. If the voltage is low, inspect the signal circuit for a short to ground.
Step
Action
Values
Yes
No
Schematic Reference: Engine Controls Schematics
1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls
2
Start and run the engine until normal operating temperature is reached.
With a scan tool, observe the HO2S voltage for the sensor that applies to this DTC.
Is the HO2S voltage less than the specified value?
200 mV
Go to Step 4
Go to Step 3
3
Observe the Freeze Frame/Failure Records data for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or as close to the Freeze Frame/Failure Records data that you observed.
Does the DTC fail this ignition?
--
Go to Step 4
Go to Diagnostic Aids
4
Turn OFF the ignition.
Disconnect the HO2S connector for the sensor that applies to this DTC.
Jumper the HO2S low signal circuit terminal on the engine harness side to a known good ground.
Turn ON the ignition, with the engine OFF.
Use a scan tool in order to observe the HO2S voltage.
Is the HO2S voltage within the specified range?
350-550 mV
Go to Step 5
Go to Step 6
5
The HO2S may be detecting a lean exhaust condition. Inspect for the following conditions:
Water intrusion into the HO2S connector
Exhaust leak between the HO2S and the engine
Vacuum leaks
Incorrect fuel pressure
Lean fuel injectors
Inaccurate MAF sensor
Repair any of the above or similar engine conditions as necessary.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 8
6
Turn OFF the ignition.
Disconnect the PCM connector that contains the HO2S high signal circuit. Refer to Powertrain Control Module (PCM) Replacement .
Test the HO2S high signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 7
7
Test the HO2S high signal circuit for a short to the HO2S Low signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 9
8
Inspect for poor connections at the harness connector of the HO2S. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 10
9
Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 11
10
Replace the affected HO2S. Refer to Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1 or Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1 .
Did you complete the replacement?
--
Go to Step 12
--
11
Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .
Did you complete the replacement?
--
Go to Step 12
--
12
Use the scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run and pass?
--
Go to Step 13
Go to Step 2
13
With a scan tool, observe the stored information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK
--
11
Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .
Did you complete the replacement?
--
Go to Step 12
--
12
Use the scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run and pass?
--
Go to Step 13
Go to Step 2
13
With a scan tool, observe the stored information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK
Document ID# 791149
Document ID# 791149
2002 Chevrolet Camaro
DTC P0131 or P0151
Circuit Description
The powertrain control module (PCM) supplies a voltage of about 450 mV between the heated oxygen sensor (HO2S) high and low signal circuits. The oxygen sensor (O2) varies the voltage from approximately 1,000 mV when the exhaust is rich, through approximately 10 mV when the exhaust is lean.
The PCM monitors and stores the HO2S voltage information. The PCM evaluates the HO2S voltage samples in order to determine the amount of time the HO2S voltage was out of range. The PCM compares the stored HO2S voltage samples taken within each sample period, and determines if the majority of the samples are out of the operating range.
The PCM monitors the HO2S voltage for being fixed below a predetermined voltage. If the PCM detects the voltage is below a predetermined voltage, a DTC sets.
Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0200, P0300 P0410, P0440, P0442, P0446, P0452, P0453, P1258, P1415, P1416, or P1441 are not set.
The ignition 1 signal is between 9-18 volts.
The fuel tank level remaining is more than 10 percent.
The loop status is closed.
Intrusive tests are not in progress.
Scan tool output controls are not active.
Lean Test Enable
The air fuel ratio is between 14.5:1 and 14.7:1.
The throttle position (TP) is between 3-70 percent.
Power Enrichment Test Enable
Power enrichment is active.
The above condition is met for 1 second.
Conditions for Setting the DTC
Lean Test
The HO2S voltage is less than 200 mV for 165 seconds.
Power Enrichment Test
The HO2S voltage is less than 360 mV for 10 seconds.
Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
The control module commands Open Loop.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
Important
Before you service the PCM, remove any debris from the PCM connector surfaces. Inspect the PCM connector gaskets when you diagnose or replace the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the PCM.
For any test that requires probing the PCM or component harness connectors, use the J 35616-A Connector Test Adapter Kit . Using this kit prevents any damage to the harness connector terminals. Refer to Using Connector Test Adapters in Wiring Systems.
The PCM sets this DTC when the vehicle runs out of fuel. Inspect for the following conditions:
The heated oxygen sensor (HO2S) wires--The sensor pigtail may be in contact with the exhaust manifold or the exhaust system.
The oxygen supply--An oxygen supply inside the HO2S is necessary for proper operation. The HO2S wires provide the supply of oxygen. Inspect the HO2S wires and connections for breaks or for contamination. Refer to Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems.
An intermittent ground--Inspect for an intermittent ground in the signal wire between the connector and the sensor.
Lean injectors--Perform the Injector Balance Test. Refer to Fuel Injector Balance Test with Tech 2 or Fuel Injector Balance Test with Special Tool .
Fuel contamination--Water near the in-tank fuel pump inlet can be delivered to the injectors. Refer to Alcohol/Contaminants-in-Fuel Diagnosis . The water causes a lean exhaust and can set a DTC.
The fuel pressure--If the fuel pressure is too low, the system will be lean. Refer to Fuel System Diagnosis .
Exhaust leaks--An exhaust leak near the HO2S can cause a lean condition. Refer to Exhaust Leakage in Engine Exhaust.
Vacuum or crankcase leaks can cause a lean condition.
If the above components are OK, the HO2S may be at fault.
For an intermittent condition, refer to Symptoms - Engine Controls .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
If the voltage is below the specified value, the condition is present.
A disconnected sensor should indicate a bias voltage. If the voltage is low, inspect the signal circuit for a short to ground.
Step
Action
Values
Yes
No
Schematic Reference: Engine Controls Schematics
1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls
2
Start and run the engine until normal operating temperature is reached.
With a scan tool, observe the HO2S voltage for the sensor that applies to this DTC.
Is the HO2S voltage less than the specified value?
200 mV
Go to Step 4
Go to Step 3
3
Observe the Freeze Frame/Failure Records data for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or as close to the Freeze Frame/Failure Records data that you observed.
Does the DTC fail this ignition?
--
Go to Step 4
Go to Diagnostic Aids
4
Turn OFF the ignition.
Disconnect the HO2S connector for the sensor that applies to this DTC.
Jumper the HO2S low signal circuit terminal on the engine harness side to a known good ground.
Turn ON the ignition, with the engine OFF.
Use a scan tool in order to observe the HO2S voltage.
Is the HO2S voltage within the specified range?
350-550 mV
Go to Step 5
Go to Step 6
5
The HO2S may be detecting a lean exhaust condition. Inspect for the following conditions:
Water intrusion into the HO2S connector
Exhaust leak between the HO2S and the engine
Vacuum leaks
Incorrect fuel pressure
Lean fuel injectors
Inaccurate MAF sensor
Repair any of the above or similar engine conditions as necessary.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 8
6
Turn OFF the ignition.
Disconnect the PCM connector that contains the HO2S high signal circuit. Refer to Powertrain Control Module (PCM) Replacement .
Test the HO2S high signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 7
7
Test the HO2S high signal circuit for a short to the HO2S Low signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 9
8
Inspect for poor connections at the harness connector of the HO2S. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 10
9
Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 11
10
Replace the affected HO2S. Refer to Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1 or Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1 .
Did you complete the replacement?
--
Go to Step 12
--
11
Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .
Did you complete the replacement?
--
Go to Step 12
--
12
Use the scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run and pass?
--
Go to Step 13
Go to Step 2
13
With a scan tool, observe the stored information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK
07-14-2013, 07:32 PM
#10
Document ID# 778825
Chevrolet Camaro
DTC P0300
System Description
The powertrain control module (PCM) uses information from the crankshaft position (CKP) sensors and from the camshaft position (CMP) sensor in order to determine if engine misfire is occurring. By monitoring the variations in the crankshaft rotational speed for each cylinder, the PCM is able to detect individual cylinder misfire events. A misfire rate that is high enough can cause damage to the 3-way catalytic converter. The malfunction indicator lamp (MIL) will flash if converter-damaging conditions are present.
Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0335, P0336, P0341, P0342, P0343, P0500, P0502, P0503, and P1258 are not set.
The engine speed is between 450-3,001 RPM.
The ignition voltage is between 10-18 volts.
The engine coolant temperature is between -7°C (19°F)-130°C (266°F).
The fuel level is more than 10 percent.
The throttle position (TP) sensor angle is steady within 1 percent.
The anti-lock brake system (ABS) system and the traction control system are not active.
The transmission is not changing gears.
The secondary air injection (AIR) diagnostic test is not in progress.
The A/C clutch is not changing states.
The PCM is not in fuel shut-off mode or decel fuel cut-off mode.
The ABS signals not exceeding the rough road thresholds.
Conditions for Setting the DTC
The PCM determines that an emissions-type misfire is present.
The PCM determines that a catalyst-damaging misfire is present.
Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
Important
Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when you diagnose or replace the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the PCM.
For any test that requires probing the PCM or component harness connectors, use the J 35616-A connector test adapter kit . Using this kit prevents any damage to the harness connector terminals. Refer to Using Connector Test Adapters in Wiring Systems.
The following conditions may cause a misfire:
Running the vehicle out of fuel causes sufficient misfire to set DTC P0300. A vehicle that is out of fuel may have DTC P0461 also set.
A restricted fuel filter can cause sufficient misfire to set DTC P0300. Refer to Fuel System Diagnosis .
A misfire may not be apparent at idle. The misfire may only occur above idle under a load. Road-test the vehicle, and monitor the misfire current counters.
If more than one cylinder is mis-firing, the scan tool may only display one cylinder mis-firing. This condition will not be apparent until you complete the repair. Also, if an ignition coil or module ground circuit is open for one side of the engine, the scan tool may only display 2 or 3 cylinders mis-firing. Inspect the ground circuit for the ignition coil or modules on the cylinder bank of the engine that has more than one cylinder mis-firing.
Excessive vibration from sources other than the engine could cause a misfire DTC. The following conditions are possible sources of vibration:
A variable thickness brake rotor
A drive shaft that is not balanced
Certain rough road conditions
For an intermittent condition, refer to Intermittent Conditions .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
A misfire may not be apparent at idle. The misfire may only occur above idle or under a load. Road-test the vehicle, and monitor the Misfire Current Counters.
If certain DTCs set at the same time or after DTC P0300 sets, the Misfire Current Counters will not increment . Refer to conditions for running DTC P0300 for the applicable DTC list.
If more than one cylinder is misfiring, the Misfire Current Counters may increment for only one cylinder. For example, cylinder 1 and cylinder 8 are both misfiring, but only Cylinder 8 increments on the Misfire Current Counter.
If one injector fuse is open, only 2 or 3 Misfire Current Counters may increment for the corresponding side of the engine.
Wetting the secondary ignition system with water from a spray bottle may help to locate the damaged or deteriorated components. When you apply the water, look and listen for arcing or misfiring.
If the Misfire Current Counters are incrementing and there is no apparent misfire, an erratic CKP sensor signal could be the cause. If you suspect that this condition exists, perform the diagnostic test for DTC P0335 first.
If a misfire is present and you suspect a fuel control condition, force the fuel system into Open Loop using the scan tool, and allow the engine to run for a few minutes. If this procedure eliminates the misfire, refer to any fuel control related DTCs which are set. If no other DTCs are set, refer to the Engine Scan Tool Data List.
The cylinder with the more significant misfire may cause another cylinder's counter to increment by only a small amount.
If the engine misfire moves with the spark plug, this is good indication that you should replace the spark plug.
If you cannot locate a fuel system condition, refer to Engine Mechanical - 5.7L. An engine mechanical condition can cause a spark plug to gas foul. Inspect for loose rockers, and inspect for collapsed lifters or for worn camshaft lobes.
If the customer's concern is that the MIL is flashing, this indicates that a Catalyst Misfire has occurred. Drive the vehicle in the conditions to run the catalyst diagnostic.
Step
Action
Values
Yes
No
1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls
2
Important
You must perform the CKP System Variation Learn Procedure before proceeding with this diagnostic table. Refer to CKP System Variation Learn Procedure .
Before you proceed with this diagnostic, ensure that the ABS system and the Traction Control system are functioning properly.
If any DTCs, other than P0135 and P0155 are set, refer to those DTCs before proceeding with this diagnostic.
Use the scan tool in order to monitor all the Misfire Current Counters on the misfire data list. There are 8 counters, with one counter per cylinder.
Are any of the Misfire Current Counters incrementing?
--
Go to Step 4
Go to Step 3
3
Turn ON the ignition, with the engine OFF.
Review the Freeze Frame/Failure Records data for this DTC, and observe the parameters.
Turn OFF the ignition for 15 seconds.
Start the engine.
Operate the vehicle within the conditions required for this diagnostic to run. Attempt to duplicate the conditions recorded in the Freeze Frame/Failure Records. Special operating conditions that you must meet before the PCM will run this diagnostic, where applicable, are listed in Conditions for Running the DTC.
Select the Diagnostic Trouble Code (DTC) option.
Does the scan tool indicate that this diagnostic failed this ignition?
--
Go to Step 4
Go to Diagnostic Aids
4
Is only one Misfire Counter incrementing?
--
Go to Step 6
Go to Step 5
5
Inspect the following items:
Observe the HO2S readings on the scan tool. If the signal is fixed below 200 mV refer to DTC P0131 or P0151 . If the signal is fixed above 900 mV refer to DTC P0132 or P0152 .
Inspect the accessory drive belt and the pulleys for damage or misalignment. Refer to Drive Belt Excessive Wear Diagnosis in Engine Mechanical-5.7L.
Inspect the vacuum hoses for splits, for kinks, and for correct connections. Refer to Emission Hose Routing Diagram .
Inspect the throttle body and the intake manifold for vacuum leaks.
Inspect the crankcase ventilation valve and/or system for vacuum leaks. Refer to Crankcase Ventilation System Inspection/Description in Engine Mechanical-5.7L .
Inspect the PCM grounds for being clean and secure. Refer to Ground Distribution Schematics in Wiring Systems.
Verify that all injector harness connectors are connected to the proper injector and/or cylinder.
Inspect the injector and the Ignition Control fuses for being open. If you find an open fuse, locate and repair the shorted circuit. Refer to Wiring Repairs in Wiring Systems.
Test for low fuel pressure or for restricted fuel flow. Refer to Fuel System Diagnosis .
Inspect for a restricted exhaust. Refer to Restricted Exhaust in Engine Exhaust.
Inspect for fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
Did any of the above tests isolate a condition requiring a repair?
--
Go to Step 17
Go to Step 6
Chevrolet Camaro
DTC P0300
System Description
The powertrain control module (PCM) uses information from the crankshaft position (CKP) sensors and from the camshaft position (CMP) sensor in order to determine if engine misfire is occurring. By monitoring the variations in the crankshaft rotational speed for each cylinder, the PCM is able to detect individual cylinder misfire events. A misfire rate that is high enough can cause damage to the 3-way catalytic converter. The malfunction indicator lamp (MIL) will flash if converter-damaging conditions are present.
Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0335, P0336, P0341, P0342, P0343, P0500, P0502, P0503, and P1258 are not set.
The engine speed is between 450-3,001 RPM.
The ignition voltage is between 10-18 volts.
The engine coolant temperature is between -7°C (19°F)-130°C (266°F).
The fuel level is more than 10 percent.
The throttle position (TP) sensor angle is steady within 1 percent.
The anti-lock brake system (ABS) system and the traction control system are not active.
The transmission is not changing gears.
The secondary air injection (AIR) diagnostic test is not in progress.
The A/C clutch is not changing states.
The PCM is not in fuel shut-off mode or decel fuel cut-off mode.
The ABS signals not exceeding the rough road thresholds.
Conditions for Setting the DTC
The PCM determines that an emissions-type misfire is present.
The PCM determines that a catalyst-damaging misfire is present.
Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
Important
Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when you diagnose or replace the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the PCM.
For any test that requires probing the PCM or component harness connectors, use the J 35616-A connector test adapter kit . Using this kit prevents any damage to the harness connector terminals. Refer to Using Connector Test Adapters in Wiring Systems.
The following conditions may cause a misfire:
Running the vehicle out of fuel causes sufficient misfire to set DTC P0300. A vehicle that is out of fuel may have DTC P0461 also set.
A restricted fuel filter can cause sufficient misfire to set DTC P0300. Refer to Fuel System Diagnosis .
A misfire may not be apparent at idle. The misfire may only occur above idle under a load. Road-test the vehicle, and monitor the misfire current counters.
If more than one cylinder is mis-firing, the scan tool may only display one cylinder mis-firing. This condition will not be apparent until you complete the repair. Also, if an ignition coil or module ground circuit is open for one side of the engine, the scan tool may only display 2 or 3 cylinders mis-firing. Inspect the ground circuit for the ignition coil or modules on the cylinder bank of the engine that has more than one cylinder mis-firing.
Excessive vibration from sources other than the engine could cause a misfire DTC. The following conditions are possible sources of vibration:
A variable thickness brake rotor
A drive shaft that is not balanced
Certain rough road conditions
For an intermittent condition, refer to Intermittent Conditions .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
A misfire may not be apparent at idle. The misfire may only occur above idle or under a load. Road-test the vehicle, and monitor the Misfire Current Counters.
If certain DTCs set at the same time or after DTC P0300 sets, the Misfire Current Counters will not increment . Refer to conditions for running DTC P0300 for the applicable DTC list.
If more than one cylinder is misfiring, the Misfire Current Counters may increment for only one cylinder. For example, cylinder 1 and cylinder 8 are both misfiring, but only Cylinder 8 increments on the Misfire Current Counter.
If one injector fuse is open, only 2 or 3 Misfire Current Counters may increment for the corresponding side of the engine.
Wetting the secondary ignition system with water from a spray bottle may help to locate the damaged or deteriorated components. When you apply the water, look and listen for arcing or misfiring.
If the Misfire Current Counters are incrementing and there is no apparent misfire, an erratic CKP sensor signal could be the cause. If you suspect that this condition exists, perform the diagnostic test for DTC P0335 first.
If a misfire is present and you suspect a fuel control condition, force the fuel system into Open Loop using the scan tool, and allow the engine to run for a few minutes. If this procedure eliminates the misfire, refer to any fuel control related DTCs which are set. If no other DTCs are set, refer to the Engine Scan Tool Data List.
The cylinder with the more significant misfire may cause another cylinder's counter to increment by only a small amount.
If the engine misfire moves with the spark plug, this is good indication that you should replace the spark plug.
If you cannot locate a fuel system condition, refer to Engine Mechanical - 5.7L. An engine mechanical condition can cause a spark plug to gas foul. Inspect for loose rockers, and inspect for collapsed lifters or for worn camshaft lobes.
If the customer's concern is that the MIL is flashing, this indicates that a Catalyst Misfire has occurred. Drive the vehicle in the conditions to run the catalyst diagnostic.
Step
Action
Values
Yes
No
1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls
2
Important
You must perform the CKP System Variation Learn Procedure before proceeding with this diagnostic table. Refer to CKP System Variation Learn Procedure .
Before you proceed with this diagnostic, ensure that the ABS system and the Traction Control system are functioning properly.
If any DTCs, other than P0135 and P0155 are set, refer to those DTCs before proceeding with this diagnostic.
Use the scan tool in order to monitor all the Misfire Current Counters on the misfire data list. There are 8 counters, with one counter per cylinder.
Are any of the Misfire Current Counters incrementing?
--
Go to Step 4
Go to Step 3
3
Turn ON the ignition, with the engine OFF.
Review the Freeze Frame/Failure Records data for this DTC, and observe the parameters.
Turn OFF the ignition for 15 seconds.
Start the engine.
Operate the vehicle within the conditions required for this diagnostic to run. Attempt to duplicate the conditions recorded in the Freeze Frame/Failure Records. Special operating conditions that you must meet before the PCM will run this diagnostic, where applicable, are listed in Conditions for Running the DTC.
Select the Diagnostic Trouble Code (DTC) option.
Does the scan tool indicate that this diagnostic failed this ignition?
--
Go to Step 4
Go to Diagnostic Aids
4
Is only one Misfire Counter incrementing?
--
Go to Step 6
Go to Step 5
5
Inspect the following items:
Observe the HO2S readings on the scan tool. If the signal is fixed below 200 mV refer to DTC P0131 or P0151 . If the signal is fixed above 900 mV refer to DTC P0132 or P0152 .
Inspect the accessory drive belt and the pulleys for damage or misalignment. Refer to Drive Belt Excessive Wear Diagnosis in Engine Mechanical-5.7L.
Inspect the vacuum hoses for splits, for kinks, and for correct connections. Refer to Emission Hose Routing Diagram .
Inspect the throttle body and the intake manifold for vacuum leaks.
Inspect the crankcase ventilation valve and/or system for vacuum leaks. Refer to Crankcase Ventilation System Inspection/Description in Engine Mechanical-5.7L .
Inspect the PCM grounds for being clean and secure. Refer to Ground Distribution Schematics in Wiring Systems.
Verify that all injector harness connectors are connected to the proper injector and/or cylinder.
Inspect the injector and the Ignition Control fuses for being open. If you find an open fuse, locate and repair the shorted circuit. Refer to Wiring Repairs in Wiring Systems.
Test for low fuel pressure or for restricted fuel flow. Refer to Fuel System Diagnosis .
Inspect for a restricted exhaust. Refer to Restricted Exhaust in Engine Exhaust.
Inspect for fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
Did any of the above tests isolate a condition requiring a repair?
--
Go to Step 17
Go to Step 6
07-14-2013, 07:32 PM
#11
[continued]
6
Turn OFF the ignition.
Disconnect the injector that corresponds to any Misfire Current Counter that was incrementing.
Connect the J 34730-2C injector test lamp to the injector electrical connector.
Idle the engine.
Is the injector test lamp flashing?
--
Go to Step 7
Go to DTC P0200
7
Turn OFF the ignition.
Reconnect the injector harness electrical connector.
Disconnect the ignition wires from any spark plug that corresponds to any Misfire Current Counter that is incrementing.
Install J 26792 spark tester to ground.
Start the engine.
Does the spark jump the tester gap, and is the spark consistent?
--
Go to Step 9
Go to Step 8
8
Remove the ignition wire for the cylinder that is misfiring.
Use the DMM in order to measure the resistance of the ignition wire.
Is the ignition wire resistance less than the specified resistance?
700 ohms
Go to Electronic Ignition (EI) System Diagnosis
Go to Step 16
9
Remove the spark plugs from the cylinder that indicated a misfire. Refer to Ignition Coil(s) Replacement .
Inspect the spark plugs. Refer to Spark Plug Inspection .
Does the spark plug appear to be OK?
--
Go to Step 10
Go to Step 11
10
Important
If the Injector Coil Test Procedure does not isolate the condition, refer to Base Engine Misfire without Internal Engine Noises in Engine Mechanical-5.7L.
Swap the suspected spark plug with another cylinder that is operating properly.
Operate the vehicle under the same conditions that the misfire occurred.
Did the misfire move with the spark plug?
--
Go to Step 15
Go to Fuel Injector Coil Test
11
Are the spark plugs oil or coolant fouled?
--
Go to Base Engine Misfire with Coolant Consumption or Base Engine Misfire with Excessive Oil Consumption in Engine Mechanical-5.7L
Go to Step 12
12
Important
If the Fuel System is OK, refer to Base Engine Misfire without Internal Engine Noises in Engine Mechanical-5.7L.
Are the spark plugs gas-fouled?
--
Go to Fuel System Diagnosis
Go to Step 13
13
Important
If the Injector Coil Test Procedure does not isolate the condition, refer to Base Engine Misfire without Internal Engine Noises in Engine Mechanical-5.7L.
Do the spark plugs show any signs of being cracked, worn, or improperly gapped?
--
Go to Step 14
Go to Fuel Injector Coil Test
14
Replace or re-gap spark plugs.
If improper gap is found, be sure to re-gap spark plugs using a wire type gauge.
Is the action complete?
--
Go to Step 17
--
15
Replace the faulty spark plugs. Refer to Spark Plug Replacement .
Did you complete the replacement?
--
Go to Step 17
--
16
Replace the faulty ignition wires. Refer to Spark Plug Wire Replacement .
Did you complete the replacement?
--
Go to Step 17
--
17
Was the customer's concern that the MIL was flashing?
--
Go to DTC P0420 or P0430
Go to Step 18
18
Use the scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run and pass?
--
Go to Step 19
Go to Step 2
19
With a scan tool, observe the stored information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK
6
Turn OFF the ignition.
Disconnect the injector that corresponds to any Misfire Current Counter that was incrementing.
Connect the J 34730-2C injector test lamp to the injector electrical connector.
Idle the engine.
Is the injector test lamp flashing?
--
Go to Step 7
Go to DTC P0200
7
Turn OFF the ignition.
Reconnect the injector harness electrical connector.
Disconnect the ignition wires from any spark plug that corresponds to any Misfire Current Counter that is incrementing.
Install J 26792 spark tester to ground.
Start the engine.
Does the spark jump the tester gap, and is the spark consistent?
--
Go to Step 9
Go to Step 8
8
Remove the ignition wire for the cylinder that is misfiring.
Use the DMM in order to measure the resistance of the ignition wire.
Is the ignition wire resistance less than the specified resistance?
700 ohms
Go to Electronic Ignition (EI) System Diagnosis
Go to Step 16
9
Remove the spark plugs from the cylinder that indicated a misfire. Refer to Ignition Coil(s) Replacement .
Inspect the spark plugs. Refer to Spark Plug Inspection .
Does the spark plug appear to be OK?
--
Go to Step 10
Go to Step 11
10
Important
If the Injector Coil Test Procedure does not isolate the condition, refer to Base Engine Misfire without Internal Engine Noises in Engine Mechanical-5.7L.
Swap the suspected spark plug with another cylinder that is operating properly.
Operate the vehicle under the same conditions that the misfire occurred.
Did the misfire move with the spark plug?
--
Go to Step 15
Go to Fuel Injector Coil Test
11
Are the spark plugs oil or coolant fouled?
--
Go to Base Engine Misfire with Coolant Consumption or Base Engine Misfire with Excessive Oil Consumption in Engine Mechanical-5.7L
Go to Step 12
12
Important
If the Fuel System is OK, refer to Base Engine Misfire without Internal Engine Noises in Engine Mechanical-5.7L.
Are the spark plugs gas-fouled?
--
Go to Fuel System Diagnosis
Go to Step 13
13
Important
If the Injector Coil Test Procedure does not isolate the condition, refer to Base Engine Misfire without Internal Engine Noises in Engine Mechanical-5.7L.
Do the spark plugs show any signs of being cracked, worn, or improperly gapped?
--
Go to Step 14
Go to Fuel Injector Coil Test
14
Replace or re-gap spark plugs.
If improper gap is found, be sure to re-gap spark plugs using a wire type gauge.
Is the action complete?
--
Go to Step 17
--
15
Replace the faulty spark plugs. Refer to Spark Plug Replacement .
Did you complete the replacement?
--
Go to Step 17
--
16
Replace the faulty ignition wires. Refer to Spark Plug Wire Replacement .
Did you complete the replacement?
--
Go to Step 17
--
17
Was the customer's concern that the MIL was flashing?
--
Go to DTC P0420 or P0430
Go to Step 18
18
Use the scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run and pass?
--
Go to Step 19
Go to Step 2
19
With a scan tool, observe the stored information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK
