GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The 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

Tested during crank/PCM power up.

Conditions for Setting the DTC

The PCM does not contain the correct program required to operate the vehicle, or has not been programmed.

Action Taken When the DTC Sets

    • The PCM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
    • The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame and/or Failure Records.

Conditions for Clearing the MIL/DTC

    • The PCM turns the MIL Off after three consecutive drive trips that the diagnostic runs and does not fail.
    • A last test failed (current DTC) clears when the diagnostic runs and does not fail.
    • A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
    • Use a scan tool in order to clear the MIL/DTC.
    • Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module (PCM) Description , Clearing Diagnostic Trouble Codes.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.

Step

Action

Value(s)

Yes

No

1

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

--

Go to Step 2

Go to the Powertrain On Board Diagnostic (OBD) System Check

2

Re-program the PCM with the correct software. Refer to Powertrain Control Module Replacement/Programming

Is the action complete?

--

Go to Step 4

--

3

Replace the PCM.

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

Is action complete?

--

Go to Step 4

--

4

  1. Clear DTCs with the scan tool.
  2. Turn the key to Off and wait 15 seconds.
  3. Start and run the vehicle.

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

--

Go to Step 5

Go to Step 3

5

Review Captured Info using the scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to the applicable DTC table

System OK