DTC P0604 Internal Control Module Random Access Memory (RAM) Error
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 (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.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
ECM RAM errors:
INSPECTION PROCEDURE
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, 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 ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0604)
Result
REPLACE ECM
Fog light switch
The fog lights secure excellent visibility in difficult driving
conditions,
such as in rain and fog.
The illustration is intended as an example.
Turns the fog lights on
*1 or
*2
Turns the fog lights off
*1: For U.S.A.
*2: For Canada
Fog lights can be used when
The headlights ...
Terminals of ECU
1. JUNCTION CONNECTOR
Junction connector
with VSC
HINT:
*1: with Dynamic laser cruise control
without VSC
CAN junction connector (with VSC)
with VSC
The connection diagram of the components which
are connected to the CAN junction connector.
2. DLC3
...
Reassembly
1. INSTALL INSTR PNL PASS L/DOOR AIR BAG
ASSEMBLY
2. INSTALL INSTRUMENT PANEL WIRE NO.2
3. INSTALL NAVIGATION ANTENNA ASSEMBLY
4. INSTALL ANTENNA CORD SUB-ASSEMBLY
5. INSTALL INSTRUMENT PANEL BOX DOOR SUBASSEMBLY
NO.2
6. INSTALL INSTRUMENT PANEL FINISH PANEL
RETAINER NO.1
7. INSTALL INSTRUM ...