GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The Powertrain Control Module (PCM) used in this vehicle utilizes an electrically erasable programmable read-only memory (EEPROM). The EEPROM contains program information and the calibrations required for powertrain diagnostics operation. Unlike the PROM used in past applications, the EEPROM is not replaceable. When the PCM is replaced or a calibration update is required, the PCM must be programmed using approved Techline equipment.

Conditions for Running the DTC

The ignition is in the Start or Run position.

Conditions for Setting the DTC

The PCM does not contain the correct program required to operate the vehicle.

Action Taken When the DTC Sets

    • The malfunction indicator lamp (MIL) will illuminate.
    • The PCM will attempt to record the operating conditions at the time during which you detect this failure, however, since this is a internal PCM failure, you cannot rely on this information. This information will store in the Freeze Frame and Failure Records buffers.
    • A history DTC stores.

Conditions for Clearing the MIL/DTC

    • The MIL will turn off after 3 consecutive ignition cycles in which the diagnostic runs without a fault.
    • A history DTC will clear after 40 consecutive warm up cycles without a fault.
    • Use a scan tool to clear the DTCs.

Test Description

The number below refers to the step number on the diagnostic table.

  1. The replacement PCM must be programmed and the Crankshaft Position System Variation Learn procedure must be performed.

DTC Memory

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the repair?

--

Go to Step 3

--

3

  1. Use a scan tool in order to clear the DTCs.
  2. 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