| DTC Code | DTC Name |
|---|---|
| P0604 | Internal Control Module Random Access Memory (RAM) Error |
| P0606 | ECM / PCM Processor |
| P0607 | Control Module Performance |
| P0657 | Actuator Supply Voltage Circuit / Open |
DESCRIPTION
The ECM continuously monitors its own internal memory status, internal circuits, and output signals transmitted to the throttle actuator. This self-check ensures that the ECM is functioning properly. If any malfunction is detected, the ECM sets the appropriate DTC and illuminates the MIL.
The ECM memory status is diagnosed by internal mirroring of the main CPU and the sub CPU to detect random access memory errors. The two CPUs also perform continuous mutual monitoring. The ECM illuminates the MIL and sets a DTC if: 1) outputs from the two CPUs are different or deviate from the standards, 2) the signals sent to the throttle actuator deviate from the standards, 3) a malfunction is found in the throttle actuator supply voltage, and 4) any other ECM malfunction is found.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0604 P0606 P0607 P0657 |
ECM internal error (1 trip detection logic) | ECM |
INSPECTION PROCEDURE
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
PROCEDURE
REPLACE ECM
Replace the ECM (Click here).
END