The powertrain control module (PCM) has detected a failure in the communication circuitry.
The ignition is ON.
An error was detected in the EEPROM data readout.
• | The PCM illuminates the malfunction indicator lamp (MIL). |
• | The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame buffer. |
• | The MIL turns OFF after 3 consecutively passing trips without a fault present. |
• | A history DTC clears after 40 consecutive warm-up cycles without a fault. |
• | Perform the scan tool Clear DTC Information function. |
Check the PCM for water contamination. Water entering the PCM can cause damage and corrosion to the circuit boards and to internal components. Repair the source of the water entry before the installation of a replacement PCM.
A DTC P0601 can set if an incorrect PCM is installed in the vehicle. Install the correct PCM according to the vehicle and/or the engine type and equipment options.
The numbers below refer to the step numbers in the diagnostic table.
The Diagnostic System Check-Engine Controls prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
This step determines if the fault is present. Replace the PCM if this DTC sets again.
Step | Action | Yes | No |
---|---|---|---|
Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | ||
Important: If the vehicle does not start, crank the engine in order to allow the DTC to set.
Does the scan tool indicate a DTC P0601? | Go to Step 3 | Go to Diagnostic Aids | |
3 | Replace the PCM. Refer to Powertrain Control Module Replacement . Is the action complete? | Go to Step 4 | -- |
4 |
Does the DTC run and pass? | Go to Step 5 | Go to Step 2 |
5 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | System OK |