C1633
C1633 4WAS FRONT CONTROL UNITDescription
^ Each sensor signal controls 4WAS front actuator.
^ The fail-safe functions stops the rear wheel angle function (the front wheel is the steering wheel cutting angle) when the electric components and the mechanical components are malfunctioning.
^ The protection function stops 4WAS system temporarily when:
- 4WAS system continues being high load/overheat condition.
- The input signal is not transmitted to 4WAS front control unit.
^ 4WAS front control unit and 4WAS main control unit control the 4WAS system by 4WAS communication line to optimize control.
DTC Logic
C1633:
DTC CONFIRMATION PROCEDURE
1.RECHECK DTC
With CONSULT-III
1. Turn the ignition switch from OFF to ON.
2. Perform 4WAS front control unit self-diagnosis.
Is DTC "C1633" detected?
YES >> Proceed to diagnosis procedure. Refer to "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
1.CHECK 4WAS FRONT CONTROL UNIT (1)
With CONSULT-III
1. Start the engine.
CAUTION:
Stop the vehicle.
2. Check "THERM TEMP" on DATA MONITOR of 4WAS front control unit.
3. Steer the steering wheel 360° leftward slowly and then steer 360° rightward. Return the steering wheel to the straight ahead position. Repeat the same service for 3 minutes.
4. Check "THERM TEMP" on DATA MONITOR of 4WAS front control unit.
Is DATA MONITOR value difference between before and after the service 30 or less?
YES >> Replace 4WAS front control unit.
NO >> GO TO 2.
2.CHECK 4WAS FRONT CONTROL UNIT (2)
With CONSULT-III
1. Start the engine.
CAUTION:
Stop the vehicle.
2. Check "THERM TEMP" item on "DATA MONITOR" of 4WAS front control unit.
3. Steer the steering wheel 360° leftward slowly and then steer 360° rightward. Return the steering wheel to the straight ahead position. Repeat the same service for 3 minutes.
4. Check "THERM TEMP" item on "DATA MONITOR" of 4WAS front control unit.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Replace 4WAS front control unit.
3.CHECK INFORMATION
^ Check that any item below is applicable when malfunction occurs.
- Entering and exiting the garage (Frequent steering)
- When steering the steering wheel for a long time.
Is the item applicable?
YES >> 4WAS system protection function mode (overheat protection)(4WAS system temporary stop)
NO >> Replace 4WAS front control unit.
Special Repair Requirement
BEFORE REPLACING 4WAS FRONT CONTROL UNIT
^ Record the self-diagnosis results (history).
CAUTION:
^ Never erase the memory (history) of self-diagnosis results when replacing 4WAS front control unit after diagnosis.
^ Erase the memory of the self-diagnosis results (record) after printing out or recording all the values of "DATA MONITOR".
AFTER REPLACING 4WAS FRONT CONTROL UNIT
^ Perform 4WAS front actuator adjustment after replacing 4WAS front control unit. Refer to STC-28, "4WAS FRONT ACTUATOR NEUTRAL POSITION ADJUSTMENT: Special Repair Requirement (Pattern 3)". 4WAS Front Actuator Neutral Position Adjustment