DTC    P0604    Internal Control Module Random Access Memory (RAM) Error

DTC    P0606    ECM / PCM Processor

DTC    P0607    Control Module Performance

DTC    P0657    Actuator Supply Voltage Circuit / Open

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DESCRIPTION

The ECM continuously monitors its internal memory status, internal circuits, and output signals sent to the throttle actuator. This self-check insures that the ECM is functioning properly. If any malfunction is detected, the ECM will set the appropriate DTC and illuminate 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 2 CPU also perform continuous mutual monitoring. The ECM illuminates the MIL and set a DTC if: 1) outputs from the 2 CPUs are different and 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. Freeze frame data records the engine conditions when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
1.CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0604/P0606/P0607/P0657)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG).

  1. Turn the tester ON.

  1. Enter the following menus: Powertrain / Engine / DTC.

  1. Read the DTC.


Result:

Display (DTC output)
Proceed to
P0604, P0606, P0607 or P0657
A
P0604, P0606, P0607 or P0657 and other DTCs are output
B



B
GO TO RELEVANT DTC CHART
A

REPLACE ECM