P0604

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The Vehicle Control Module (VCM) contains a memory area where it stores certain data it does not needs to save when the ignition is turned OFF. This area is called the Volatile section of memory. The Volatile section of memory is cleared and then tested when the ignition is first turned ON. This diagnostic test monitors the VCMs Volatile section of memory to make sure it is stored correctly. If the information is not stored correctly, DTC P0604 will set.


CONDITIONS FOR SETTING THE DTC

If the data from the memory location does not match the test data which was just saved.


ACTION TAKEN WHEN THE DTC SETS

^ The VCM will illuminate the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.

^ The VCM will record the operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and/or Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC

^ The VCM turns the MIL OFF after 3 consecutive drive trips when the test has Run and Passed and not Failed.

^ A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the start-up coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during the same ignition cycle).

^ Use the scan tool Clear Information function.

^ Disconnect the VCM battery feed for 30 seconds.


TEST DESCRIPTION

The numbers below refer to the step numbers on the diagnostic table.

2. Replace the VCM even if this DTC exists only in history.