Circuit Description
The powertrain control module (PCM) uses an electrically erasable programmable read only memory (EEPROM). Unlike the programmable read only memory (PROM) used in earlier applications, the EEPROM is not replaceable. The only option is to replace the PCM. The replacement PCM does not contain the final program information. This requires programming of the PCM using approved Techline equipment. If the replacement PCM is not programmed, this diagnostic trouble code (DTC) will set. When the DTC sets, the PCM disables the fuel pump relay, and the fuel injectors.
Conditions for Running the DTC
| • | DTC P0601 is not set. |
| • | The ignition is ON. |
Conditions for Setting the DTC
The PCM does not contain the final software and calibration information required to operate the vehicle.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Reprogram the PCM with the correct software for the vehicle.
-
If the reprogramming attempt fails, the PCM is faulty.
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | |
Program the PCM with the CORRECT software. Does DTC P0602 reset? | Go to Step 3 | ||
Replace the PCM. Refer to Powertrain Control Module Replacement . Is the action complete? | -- |
