P0604

Diagnostic Chart:

CIRCUIT DESCRIPTION
The PCM performs an internal self-test on it's Random Access Memory (RAM) or read/write memory. If this self-test fails, this DTC sets.

CONDITIONS FOR RUNNING THE DTC
- The ignition voltage is greater than 10 volts.
- The ignition is ON for 5 seconds.

CONDITIONS FOR SETTING THE DTC
The internal RAM test fails.

ACTION TAKEN WHEN THE DTC SETS
- The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
- The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame and/or the
Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The PCM turns the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
- A last test failed (current DTC) clears when the diagnostic runs and does not fail.
- A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
- The PCM battery voltage is interrupted.
- Use a scan tool in order to clear the MIL/DTC.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This DTC indicates an internal PCM problem.