P0604

CIRCUIT DESCRIPTION
The PCM copies the program information stored in the Electrically Erasable Programmable Read Only Memory (EEPROM) to the Random Access Memory (RAM). This allows the PCM to work with, and make any updates to the information. The PCM tests all areas of the RAM. If the PCM detects an error in any area of the RAM, DTC P0604 will set.

CONDITIONS FOR RUNNING THE DTC
The ignition is ON.

CONDITIONS FOR SETTING THE DTC
The PCM detects a malfunction in the Random Access Memory (RAM) area.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) the first time the malfunction is detected
^ The PCM will store conditions which were present when the DTC set as Freeze Frame and the Fail Records data.

DIAGNOSTIC AIDS
DTC P0604 indicates that the Random Access Memory (RAM) or an area of the RAM has malfunctioned. The PCM must be replaced. Remember to program the replacement PCM with the correct software and calibration for the vehicle.

TEST DESCRIPTION

Steps 1 - 2: