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
Wiper Signal Circuit
DESCRIPTION
The distance control ECU detects wiper operation. If the windshield wipers
operate in the HI or LO mode,
the cruise control is canceled and the warning sound "pong" is emitted once. In
addition, the following
warnings will continue until the cruise control main switch is ...
Inspection
1. INSPECT SPIDER BEARING
(a) Check that the spider bearing moves smoothly by
turning the flange.
(b) Check for the looseness around the joint by strongly
moving the flange in the axial and radial directions.
HINT:
If necessary, replace the shaft.
2. INSPECT INTERMEDIATE SHAFT
(a) Usin ...
Reassembly
1. INSTALL OIL PUMP COVER
(a) Coat the drive and driven rotors with engine oil and
place them into the timing chain cover with the
marks facing outward (oil pump cover side). Check
that the rotors rotate smoothly.
(b) Install the oil pump cover with the 8 bolts.
Torque: 9.1 N*m (93 kgf ...