SmokeU

iTrader: (2)

I have posted a few times not many responses. This is not the 1637 l terminal code . Its from the ecm to abs. I followed the lines and used a multimeter , everything checked out. No lights on the dash. but the code is stuck my preditor says that it cleared the fault but the next time i turn the ignition over it shows in the predator. Now my predator won't load a code. ANy help is appreciated.

libertyforall1776

iTrader: (2)

Does this help?

Document ID# 727377
2002 Chevrolet Camaro
DTC P1637

Circuit Description

The powertrain control module (PCM) uses the generator turn on signal circuit to control the generator. A high side driver within the PCM allows the PCM to turn the generator ON and OFF. When Generator operation is desired, the PCM sends a 5 volt signal to the voltage regulator via the generator turn on signal circuit. This causes the voltage regulator to begin controlling the generator field circuit. Once the Generator is enabled by the PCM, the voltage regulator controls generator output independently of the PCM. Under certain operating conditions, the PCM can turn Off the generator by turning Off the 5 volt signal on the generator turn on signal circuit. The PCM has fault detection circuitry which monitors the state of the generator turn on signal circuit. If the fault detection circuit senses a voltage other than what is expected, this DTC will set. The voltage regulator also contains fault detection circuitry. If the regulator detects a problem, the regulator will ground the generator turn on signal circuit, pulling the voltage low. This also causes the PCM to set the DTC.

Conditions for Running the DTC

The ignition is on.
System voltage between 9.0 and 18.0 volts.
Conditions for Setting the DTC

An improper voltage level has been detected on the alternator lamp driver circuit.
Above conditions for at least 30 seconds.
Action Taken When the DTC Sets

The PCM will not illuminate the malfunction indicator lamp (MIL).
The PCM will store conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.
Conditions for Clearing the MIL/DTC

A History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
The DTC can be cleared by using a scan tool.
Step

Action

Yes

No

Schematic Reference: Starting and Charging Schematics

1

Did you perform the Engine Electrical Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Engine Electrical

2

Turn OFF the ignition.
Disconnect the Generator.
Measure the voltage between the generator turn on signal circuit and ground.
Start the engine.
Command the Generator ON and OFF with the scan tool.
Does the voltage change between the two indicated values?

Go to Testing for Intermittent and Poor Connections in Wiring Systems

Go to Step 3

3

Test the generator turn on signal circuit for a high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 6

Go to Step 4

4

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 6

Go to Step 5

5


Important

The replacement PCM must be programmed. Refer to Powertrain Control Module (PCM) Programming in Engine Controls-5.7L.

Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls-5.7L.

Is the action complete?

Go to Step 6

--

6

Use the scan tool in order to clear the DTCs .
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?

Go to Step 2

System OK

Document ID# 727377
2002 Chevrolet Camaro

SmokeU

iTrader: (2)

Thanks for the info... Unfortunantly Thats not the problem. Any other suggestions?