SFI SYSTEM (w/ Secondary Air Injection System), Diagnostic DTC:P0604, P0606, P0607, P0657

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

MONITOR DESCRIPTION

The ECM continuously monitors its own internal memory status, internal circuits, and output signals transmitted to the throttle actuator. This self-check insures 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 (RAM) 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 Conditions Trouble Areas

P0604

P0606

P0607

P0657

 ECM internal error (1 trip detection logic)

  • ECM

INSPECTION PROCEDURE

Tech Tips

Read freeze frame data using an 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


  1. REPLACE ECM


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