GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The PCM EEPROM contains data which is essential to running the engine and transmission. The PCM continuously checks the integrity of this data.

Conditions for Clearing the MIL/DTC

    • The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
    • If no failures are reported by this or any other non-emission related diagnostic.
    • A last test failed (Current DTC) will clear when the diagnostic runs and does not fail.
    • PCM battery voltage is interrupted.
    • Using a Scan tool.

Action Taken When the DTC Sets

    • The PCM will illuminate the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
    • The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and/or Failure Records.
    • The injector will be disabled for the entire ignition cycle.

Conditions for Clearing the MIL/DTC

    • The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
    • If no failures are reported by this or any other non-emission related diagnostic.
    • A last test failed (Current DTC) will clear when the diagnostic runs and does not fail.
    • PCM battery voltage is interrupted.
    • Using a Scan tool.

Diagnostic Aids

Replace the PCM even if this DTC exists only in history.

For intermittents, refer to Symptoms .

Test Description

Number(s) below refer to step numbers on the diagnostic table.

  1. Replace the PCM even if this DTC exists only in history.

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

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

Replace the PCM.

Is the action complete?

--

Go to Step 3

--

3

  1. Using the scan tool, select DTC, Clear Info.
  2. Start the engine and idle at normal operating temperature.
  3. Select DTC, Specific, then enter the DTC number which was set.
  4. Operate the vehicle within the conditions for setting this DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test ran and passed?

--

Go to Step 4

Go to Step 2

4

Using the scan tool, select Capture Info, Review Info.

Are any DTCs displayed that have not been diagnosed?

--

Go to the applicable DTC table

System OK