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
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)
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
(e) Read DTCs.
Result
REPLACE ECM
Uniform Tire Quality Grading
This information has been prepared in accordance with regulations
issued by the National Highway Traffic Safety Administration of the
U.S. Department of Transportation.
It provides the purchasers and/or prospective purchasers of Toyota
vehicles with information on uniform tire quality grading. ...
Terminals of ECU
1. CHECK POWER SLIDE DOOR ECU LH
Disconnect the P25 and P26 ECU connectors, and
check the voltage and resistance of each terminal of
the wire harness side connectors
If the result is not as specified, there may be a
malfunction on the wire harness side.
Reconnect the EC ...
Removal
HINT:
Replace the RH side using the same procedures as for the
LH side.
1. REMOVE FRONT WHEEL
2. REMOVE FRONT AXLE HUB LH NUT (See page DS-
5)
3. SEPARATE SPEED SENSOR FRONT LH (See page
DS-5)
4. SEPARATE FRONT DISC BRAKE CALIPER ASSEMBLY LH
(a) Remove the 2 bolts and separate the front ...