Emissions test rejected because system was not ready
05-30-2015, 08:31 PM
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Emissions test rejected because system was not ready I recently bought a 2001 Z28 and I now have to get an emissions test. I did not pass because my system was not ready. I had disconnected the battery a little over a week before I went to get the test which I realize now that was a probably bad idea. The 3 systems that are not ready are: catalytic converter, secondary air and evap control. I have probably put close to 700 miles on the car since I disconnected the battery but I am still getting the same 3 systems come up as not ready. I looked into the drive cycle for GM cars and it seems a little unrealistic some of the conditions that need to be met for the test to run, here is a link to what I am referring to http://www.obdii.com/drivecycle.html I have tried doing some of them but I'm not sure if I need to follow everything in sequence or how this exactly works. Is there any better way to get these 3 systems ready, also has anyone else experienced this problem with it taking a long time for the system to be fully ready? Any help or suggestions would be appreciated. As far as I know the car is stock, the exhaust is stock and engine looks to be stock. It has 64k miles on it and the service engine light has not come on so I'm pretty sure it will pass once I get 2 of the 3 systems ready for testing.
05-30-2015, 08:46 PM
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Yes, as far as I can tell the car is stock. It still has the stock exhaust and stock air box so I am just assuming the rest of the engine is stock although I am not 100% sure.
05-31-2015, 04:04 AM
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EVAP sometimes takes quite a while to complete, it used to take forever on my '00 car but usually ran quickly on my '02. The secondary air and cat tests will usually require a cold start to run, and sometimes require other DTCs to have already completed. So the number of miles you have driven is less important than the amount of cold starts and complete drive cycles. You don't have to follow the OBD drive cycle to the letter just to get these tests to run, but it will make things happen faster.
If the car has ever had custom tuning, you may never get certain DTCs to run. If someone shut off certain O2 sensor related DTCs (rather than just disabling the SES light for said tests), then the DTC won't run and won't ever flip to complete. You'd have to get the PCM reflashed to stock or retune it (set the SES to "Type X" for those DTCs and flip the test back to "on".) But if the car was never modified then the tune is likely stock and the issue is either the fact you haven't hit enough parameters yet or some other prerequisite DTC isn't running when/how it should for some reason.
Try a few more cold starts and try following the OBD drive cycle as best you can.
EDIT: Have you checked to verify that the AIR system components are still present? Someone may have put headers and an ORY on the car at some point and just shut off the DTCs as mentioned above (especially if they lived in a place that didn't have testing). Perhaps they just re-installed the stock exhaust prior to selling the car but never returned the tune to stock. This does happen sometimes.
If the car has ever had custom tuning, you may never get certain DTCs to run. If someone shut off certain O2 sensor related DTCs (rather than just disabling the SES light for said tests), then the DTC won't run and won't ever flip to complete. You'd have to get the PCM reflashed to stock or retune it (set the SES to "Type X" for those DTCs and flip the test back to "on".) But if the car was never modified then the tune is likely stock and the issue is either the fact you haven't hit enough parameters yet or some other prerequisite DTC isn't running when/how it should for some reason.
Try a few more cold starts and try following the OBD drive cycle as best you can.
EDIT: Have you checked to verify that the AIR system components are still present? Someone may have put headers and an ORY on the car at some point and just shut off the DTCs as mentioned above (especially if they lived in a place that didn't have testing). Perhaps they just re-installed the stock exhaust prior to selling the car but never returned the tune to stock. This does happen sometimes.
Last edited by RPM WS6; 05-31-2015 at 04:13 AM.
06-01-2015, 08:58 PM
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I haven't checked to see, I am not that mechanically inclined though. Would I be looking for something that I can see externally on the engine for the AIR system components? I picked up a wireless OBD2 reader that works with my phone so I can check to see if all the systems are ready so if they are I can quickly go in for an emissions test. Any idea if I can use this same reader to check to see if the DTC codes are turned off? I don't get trouble codes with the reader that I have it just says the system is not readt and it's the same 3 systems i listed above.
06-01-2015, 11:12 PM
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The generic code readers won't show which DTCs are turned on or off, only their status (ready/not ready) and any specific DTC for which a MIL (SES light) has been commanded.
You can check the exhaust manifolds for AIR tubes leading from the top center of each manifold into a check valve (one per side), then into rubber hoses. If none of that is present, and instead you just see some sort of block-off plate on top of each manifold, then the AIR system has been removed. To see detailed pictures of these components, just do a search on this site for "AIR system removal (or delete)" and you'll get an idea of what all these items look like.
You can check the exhaust manifolds for AIR tubes leading from the top center of each manifold into a check valve (one per side), then into rubber hoses. If none of that is present, and instead you just see some sort of block-off plate on top of each manifold, then the AIR system has been removed. To see detailed pictures of these components, just do a search on this site for "AIR system removal (or delete)" and you'll get an idea of what all these items look like.
06-03-2015, 09:10 PM
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mine did this last year, and found that my battery cables were not connecting to the battery good. changed em and passed smog immediately. hope that helps. it was causing the ecu to constantly cycle im guessing.
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06-04-2015, 09:36 AM
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I went through a thing where my AIR system caused a horrible screetching noise at cold starts. A friend advise me to "pull the fuse" to get it to stop running. Promptly failed emissions.
Might want to look in your engine bay fuse panel to see if any fuses are blown or missing.
Might want to look in your engine bay fuse panel to see if any fuses are blown or missing.
06-04-2015, 10:33 AM
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System not ready can be caused by recently disconnecting to battery. It clears codes for a short amount of time after about 50 engine starts it usually goes back to normal, this is to prevent people from disconnecting there battery for 10 minutes and erasing a check engine light. The engine has to run for awhile to self diagnose codes over again after the power disconnect resets the computer.
06-04-2015, 02:03 PM
#10
Here's what the service manual says about EVAP emissions test.
The purpose of this test is to satisfy the enable criteria necessary in order to execute the I/M readiness diagnostics for the EVAP System. The test can be used to set the I/M System Status indicators to YES. Service Bay Tests are included on the scan tool for some systems, depending upon the vehicle make and model. The test is designed to allow the EVAP diagnostic tests to run during service bay conditions. Before you perform either EVAP system test, ensure that the vehicle meets the requirements listed in the Conditions for Running the DTC. Failure to meet the necessary requirements may produce inaccurate test results.
Conditions for Running
Non Scan Tool Service Bay Test Equipped Vehicles
The barometric pressure is more than 75 kPa.
The fuel level is between 1/4 and 3/4 full.
The battery voltage is between 10-18 volts.
The test will initiate only after a cold start. If the following conditions are met, the control module considers the engine to be cold:
The engine coolant temperature (ECT) is between 3.75-30°C (39-86°F).
The intake air temperature (IAT) is between 3.75-30°C (39-86°F).
The difference between the ECT and the IAT is less than 8°C (14°F).
Scan Tool Service Bay Test Equipped Vehicles
The BARO is more than 75 kPa.
The ECT is less than 80°C (176°F).
The fuel level is between 1/4 and 3/4 full.
The battery voltage is between 10-18 volts.
Diagnostic Aids
Extreme high or low ambient temperatures may prevent the EVAP System Tests from initiating. Inspecting the system prior to running the EVAP Service Bay Test may prevent having to repeat the test. A loose fuel cap may cause a Service Bay Test to abort or to fail, and prevent the I/M System Status from updating. A failed or aborted test will require the vehicle to cool down in order to meet the enable criteria to run another test.
The I/M System Status does not indicate whether the test has passed or failed, only that a decision was made. When all of the diagnostics for a specific system have run and passed, the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the required tests have not run. When a failure occurs, the Emission Related DTC portion of the I/M System Status display will indicate the malfunction indicator lamp (MIL) is requested. The I/M System Status also registers the number of diagnostic trouble codes (DTCs).
The first failure of a type B DTC does not constitute a final determination of pass or fail, and will not update the I/M System Status to YES. A second trip is required, and all the conditions to run must be met in order for the test to run again. These conditions may include a partial to complete engine cool down.
The I/M System Status will update only when an emission related DTC fails the second time, or when all of the tests pass.
If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load, such as a cooling fan or an A/C compressor clutch turning ON, may cause the test to abort.
If a diagnostic test is difficult to run, maintain necessary enable conditions until the system status updates to YES.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Before you perform this test, you must perform the I/M System Check. Failure to do so may result in difficulty updating the status to YES.
This step is to determine whether or not the EVAP System Test has passed. If the system is operating correctly, the scan tool indicates that the system has passed and the I/M System Status updates to YES. If the EVAP Service Bay Test aborts because of lost enable conditions, the test can be repeated once the enable criteria is met.
A failed DTC during the EVAP Service Bay Test may not appear in the DTC Information display on some vehicles. The Service Bay Test displays an indication of which test failed as a directive to the appropriate service information. Some vehicles will display the test as aborted and the first failure of type B DTC appears in the DTC Information.
The EVAP System Test usually begins with an engine coolant temperature of approximately 4°C (39°F). The vehicle should be operated moderately until this temperature is reached. Use the scan tool in order to monitor the engine coolant temperature.
This step is to identify a first failure of a type B DTC. A DTC only appears on the I/M System Status display when the DTC becomes a MIL-illuminating DTC. This occurs on the second failure of a type B DTC. A first failure of a type B DTC will not allow the I/M System Status to update to YES. Refer to Diagnostic Aids.
This step helps to identify any unique or unusual criteria that are required to run the diagnostic test if the universal set procedure does not. This information is located in the service information under Conditions for Running the DTC.
The I/M System Status only reports on whether or not a diagnostic has run, not the outcome. If any emissions-related DTC sets after the tests are complete, the DTC will require diagnosis.
Step
Action
Yes
No
1
Did you perform the Inspection/Maintenance (I/M) System Check?
Go to Step 2
Go to Inspection/Maintenance (I/M) System Check
2
Using a scan tool, select Special Functions.
Determine if the vehicle is equipped with a Service Bay Test for the EVAP system.
Is the vehicle equipped with EVAP Service Bay Test?
Go to Step 3
Go to Step 5
3
Ensure that the vehicle is within the Conditions for Running the DTC, as specified in the supporting text.
Turn OFF all of the accessories, including the A/C and the blower fan.
Follow the directions on the scan tool, and perform the EVAP Service Bay Test.
Did the EVAP system pass the Service Bay Test?
Go to Step 8
Go to Step 4
4
Observe the scan tool Service Bay Test to determine why the test did not pass. Examples include failed DTC, or test aborted.
Refer to the appropriate service information in order to diagnose and repair the condition.
Did you complete the repair?
Go to Service Bay Test
--
5
Ensure the vehicle is within the Conditions for Running specified in the supporting text.
Turn OFF all of the accessories, including the A/C and the blower fan.
Important
Once you start the engine, DO NOT turn the engine OFF for the remainder of the procedure until the test is complete.
Start the engine, and idle the engine.
Caution
Road test a vehicle under safe conditions and while obeying all traffic laws. Do not attempt any maneuvers that could jeopardize vehicle control. Failure to adhere to these precautions could lead to serious personal injury and vehicle damage.
Important
In order for this test to run, the vehicle must operate in the following conditions:
Acceleration at part throttle to 72 km/h (45 mph), with this speed maintained until the engine reaches the operating temperature. This process may require 8-10 minutes, depending on the start-up coolant temperature.
After the engine reaches the operating temperature, continue the operating conditions for an additional 3 minutes, or until the I/M System Status indicator updates to YES.
Did the EVAP System Status update to YES?
Go to Step 8
Go to Step 6
6
With a scan tool, observe the DTC Information.
Does the scan tool indicate any failed DTCs?
Go to Diagnostic Trouble Code (DTC) List
Go to Step 7
7
Refer to Inspection/Maintenance (I/M) System DTC Table to determine which DTCs are required to run in order to complete this test.
With a scan tool, observe the Not Ran Since Code Cleared display.
Determine which of the DTCs required for a YES status has not run.
Enter the DTC number in the Specific DTC menu of the scan tool.
Operate the vehicle within the Conditions for Running the DTC, located in the supporting text.
Repeat the procedure until the scan tool indicates the diagnostic test has run.
Repeat steps 4-6 for any additional required DTCs that have not run.
With a scan tool, observe the I/M System Status display.
Did the EVAP System Status update to YES?
Go to Step 8
Go to Diagnostic Aids
8
With a scan tool, observe the Emission Related DTC portion of the I/M System Status display.
Does the scan tool indicate that any emissions-related DTCs set?
Go to Diagnostic Trouble Code (DTC) List
System OK
The purpose of this test is to satisfy the enable criteria necessary in order to execute the I/M readiness diagnostics for the EVAP System. The test can be used to set the I/M System Status indicators to YES. Service Bay Tests are included on the scan tool for some systems, depending upon the vehicle make and model. The test is designed to allow the EVAP diagnostic tests to run during service bay conditions. Before you perform either EVAP system test, ensure that the vehicle meets the requirements listed in the Conditions for Running the DTC. Failure to meet the necessary requirements may produce inaccurate test results.
Conditions for Running
Non Scan Tool Service Bay Test Equipped Vehicles
The barometric pressure is more than 75 kPa.
The fuel level is between 1/4 and 3/4 full.
The battery voltage is between 10-18 volts.
The test will initiate only after a cold start. If the following conditions are met, the control module considers the engine to be cold:
The engine coolant temperature (ECT) is between 3.75-30°C (39-86°F).
The intake air temperature (IAT) is between 3.75-30°C (39-86°F).
The difference between the ECT and the IAT is less than 8°C (14°F).
Scan Tool Service Bay Test Equipped Vehicles
The BARO is more than 75 kPa.
The ECT is less than 80°C (176°F).
The fuel level is between 1/4 and 3/4 full.
The battery voltage is between 10-18 volts.
Diagnostic Aids
Extreme high or low ambient temperatures may prevent the EVAP System Tests from initiating. Inspecting the system prior to running the EVAP Service Bay Test may prevent having to repeat the test. A loose fuel cap may cause a Service Bay Test to abort or to fail, and prevent the I/M System Status from updating. A failed or aborted test will require the vehicle to cool down in order to meet the enable criteria to run another test.
The I/M System Status does not indicate whether the test has passed or failed, only that a decision was made. When all of the diagnostics for a specific system have run and passed, the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the required tests have not run. When a failure occurs, the Emission Related DTC portion of the I/M System Status display will indicate the malfunction indicator lamp (MIL) is requested. The I/M System Status also registers the number of diagnostic trouble codes (DTCs).
The first failure of a type B DTC does not constitute a final determination of pass or fail, and will not update the I/M System Status to YES. A second trip is required, and all the conditions to run must be met in order for the test to run again. These conditions may include a partial to complete engine cool down.
The I/M System Status will update only when an emission related DTC fails the second time, or when all of the tests pass.
If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load, such as a cooling fan or an A/C compressor clutch turning ON, may cause the test to abort.
If a diagnostic test is difficult to run, maintain necessary enable conditions until the system status updates to YES.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Before you perform this test, you must perform the I/M System Check. Failure to do so may result in difficulty updating the status to YES.
This step is to determine whether or not the EVAP System Test has passed. If the system is operating correctly, the scan tool indicates that the system has passed and the I/M System Status updates to YES. If the EVAP Service Bay Test aborts because of lost enable conditions, the test can be repeated once the enable criteria is met.
A failed DTC during the EVAP Service Bay Test may not appear in the DTC Information display on some vehicles. The Service Bay Test displays an indication of which test failed as a directive to the appropriate service information. Some vehicles will display the test as aborted and the first failure of type B DTC appears in the DTC Information.
The EVAP System Test usually begins with an engine coolant temperature of approximately 4°C (39°F). The vehicle should be operated moderately until this temperature is reached. Use the scan tool in order to monitor the engine coolant temperature.
This step is to identify a first failure of a type B DTC. A DTC only appears on the I/M System Status display when the DTC becomes a MIL-illuminating DTC. This occurs on the second failure of a type B DTC. A first failure of a type B DTC will not allow the I/M System Status to update to YES. Refer to Diagnostic Aids.
This step helps to identify any unique or unusual criteria that are required to run the diagnostic test if the universal set procedure does not. This information is located in the service information under Conditions for Running the DTC.
The I/M System Status only reports on whether or not a diagnostic has run, not the outcome. If any emissions-related DTC sets after the tests are complete, the DTC will require diagnosis.
Step
Action
Yes
No
1
Did you perform the Inspection/Maintenance (I/M) System Check?
Go to Step 2
Go to Inspection/Maintenance (I/M) System Check
2
Using a scan tool, select Special Functions.
Determine if the vehicle is equipped with a Service Bay Test for the EVAP system.
Is the vehicle equipped with EVAP Service Bay Test?
Go to Step 3
Go to Step 5
3
Ensure that the vehicle is within the Conditions for Running the DTC, as specified in the supporting text.
Turn OFF all of the accessories, including the A/C and the blower fan.
Follow the directions on the scan tool, and perform the EVAP Service Bay Test.
Did the EVAP system pass the Service Bay Test?
Go to Step 8
Go to Step 4
4
Observe the scan tool Service Bay Test to determine why the test did not pass. Examples include failed DTC, or test aborted.
Refer to the appropriate service information in order to diagnose and repair the condition.
Did you complete the repair?
Go to Service Bay Test
--
5
Ensure the vehicle is within the Conditions for Running specified in the supporting text.
Turn OFF all of the accessories, including the A/C and the blower fan.
Important
Once you start the engine, DO NOT turn the engine OFF for the remainder of the procedure until the test is complete.
Start the engine, and idle the engine.
Caution
Road test a vehicle under safe conditions and while obeying all traffic laws. Do not attempt any maneuvers that could jeopardize vehicle control. Failure to adhere to these precautions could lead to serious personal injury and vehicle damage.
Important
In order for this test to run, the vehicle must operate in the following conditions:
Acceleration at part throttle to 72 km/h (45 mph), with this speed maintained until the engine reaches the operating temperature. This process may require 8-10 minutes, depending on the start-up coolant temperature.
After the engine reaches the operating temperature, continue the operating conditions for an additional 3 minutes, or until the I/M System Status indicator updates to YES.
Did the EVAP System Status update to YES?
Go to Step 8
Go to Step 6
6
With a scan tool, observe the DTC Information.
Does the scan tool indicate any failed DTCs?
Go to Diagnostic Trouble Code (DTC) List
Go to Step 7
7
Refer to Inspection/Maintenance (I/M) System DTC Table to determine which DTCs are required to run in order to complete this test.
With a scan tool, observe the Not Ran Since Code Cleared display.
Determine which of the DTCs required for a YES status has not run.
Enter the DTC number in the Specific DTC menu of the scan tool.
Operate the vehicle within the Conditions for Running the DTC, located in the supporting text.
Repeat the procedure until the scan tool indicates the diagnostic test has run.
Repeat steps 4-6 for any additional required DTCs that have not run.
With a scan tool, observe the I/M System Status display.
Did the EVAP System Status update to YES?
Go to Step 8
Go to Diagnostic Aids
8
With a scan tool, observe the Emission Related DTC portion of the I/M System Status display.
Does the scan tool indicate that any emissions-related DTCs set?
Go to Diagnostic Trouble Code (DTC) List
System OK