P0601

Diagnostic Chart:

Circuit Description

The Powertrain Control Module (PCM) has detected a failure in the communication circuitry. If this DTC is set, the PCM must be replaced.


Conditions for Setting the DTC


EEPROM programming error.


Action Taken When the DTC Sets

- The Malfunction Indicator Lamp (MIL) will illuminate.

- The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame buffer.


Conditions for Clearing the MIL/DTC

- The MIL will turn off after three consecutive drive cycles without a fault present.

- A DTC will clear after 40 consecutive warm-up cycles without a fault.

- The DTCs can be cleared by using a scan tool or by disconnecting the PCM battery feed.

Diagnostic Aids

An intermittent malfunction may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation. Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connections before replacing the PCM.


Test Description


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

1. The Powertrain (OBD) System Check 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.

2. Determine if the fault is present. If this DTC sets again, replace the PCM. Refer to Powertrain Control Module.