P0604

Diagnostic Chart:

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) performs an internal self-test on the 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 more than 10 volts.
^ The ignition switch is in the crank or run position.
^ 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 Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS

IMPORTANT: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.

Replace the PCM even if this DTC exists only in history.

For an intermittent, refer to Symptoms. Symptom Related Diagnostic Procedures

TEST DESCRIPTION
The number below refers to the step number on the diagnostic table.
2. This DTC indicates an internal PCM condition.