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 the program information and the calibrations required for powertrain diagnostics operation.

Unlike the programmable read-only memory (PROM) used in past applications, the EEPROM is not replaceable. When the PCM is replaced or a when calibration update is required, the PCM must be programmed using approved Techline  equipment.

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 PCM will illuminate the malfunction indicator lamp (MIL) during the first trip in which the diagnostic test has been run and failed.
    • The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.

Conditions for Clearing the MIL/DTC

    • The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed.
    • The 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.

Test Description

The numbers below refer to the step numbers on the Diagnostic Table.

  1. This vehicle is equipped with a PCM which utilizes an electrically erasable programmable read-only memory (EEPROM). When you replace the PCM, you must program the new PCM.

DTC P0602 - PCM Not Programmed

Step

Action

Value(s)

Yes

No

1

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

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Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Program the PCM with correct software. Refer to Powertrain Control Module Replacement/Programming
  2. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.

Does the DTC reset?

--

Go to Step 3

System OK

3

Important:: The replacement PCM must be programmed.

Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM.

Did you complete the replacement?

--

Go to Powertrain On Board Diagnostic (OBD) System Check

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