Engine Controls - DTC P0604 Information

SOURCE: Kia PitStop

TITLE: DTC P0604 Information and Guidelines

APPLIES TO: All OBDII models

SERVICE TIP:

DTC P0604: "Internal Control Module Random Access Memory (RAM) Error" is applicable to various Kia models and model years. This DTC is intended to report an internal memory error in the control unit (ECM, TCM or PCM).

In practice, however, P0604 may also set when there is insufficient memory due to multiple other DTCs being stored at the same time.

Even though P0604 points to an internal error, more often than not the control unit is not the root cause, and should not be replaced. Should you retrieve a DTC P0604 in combination with any other DTCs, address all other DTC concerns first, then clear the control unit's memory and retest the vehicle.

If other DTCs set again, continue to resolve those. If DTC P0604 resets by itself after all other concerns have been resolved, verify that the control unit is the actual cause of the concern by swapping it with a known good one before replacing it.