C1909

C1909 4WAS MAIN CONTROL UNIT





Description
- 4WAS rear actuator and the power steering solenoid valve is controlled by each sensor signal.
- 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 protective function stops 4WAS system temporarily when the input signal is not inputted to 4WAS main control unit (When battery-power dose not work temporarily).
- 4WAS front control unit and 4WAS main control unit perform two-way transmitting/receiving signals for optimal control of 4WAS system via 4WAS communication line.




DTC Logic

DTC DETECTION LOGIC






DTC CONFIRMATION PROCEDURE
1.RECHECK DTC
With CONSULT-III
1. Turn the ignition switch from OFF to ON.
2. Perform 4WAS main control unit self-diagnosis.
Is DTC "C1909" detected?
YES - Proceed to diagnosis procedure. Refer to C1909.
NO - INSPECTION END




Diagnosis Procedure
1.CHECK 4WAS MAIN CONTROL UNIT POWER SUPPLY
1. Turn the ignition switch OFF.
2. Disconnect 4WAS main control unit harness connector.
3. Check the voltage between 4WAS main control unit harness connector terminal and the ground.





4. Turn the ignition switch ON.

CAUTION:
Never start the engine.
5. Check the voltage between 4WAS main control unit harness connector terminal and the ground.





Is the inspection result normal?
YES - GO TO 2.
NG - Check the following items. Repair or replace the malfunctioning parts.
- 10A fuse (#45) open
- Short among 10A fuse (#45) connector, 4WAS main control unit harness connector No. 27 terminal and the ground
- Open between the ignition switch and 4WAS main control unit harness connector No. 27 terminal
- Ignition switch
2.CHECK 4WAS MAIN CONTROL UNIT GROUND
Check the continuity between 4WAS main control unit harness connector and the ground.





Is the inspection result normal?
YES - GO TO 3.
NG - Repair or replace the harnesses and connectors.
3.PERFORM SELF-DIAGNOSIS (4WAS MAIN CONTROL UNIT)
With CONSULT-III
1. Connect 4WAS main control unit harness connector.
2. Perform 4WAS main control unit self-diagnosis.
Is DTC "C1909" detected?
YES - Replace 4WAS main control unit. Refer to Exploded View.
NO - GO TO 4.
4.CHECK INFORMATION
With CONSULT-III
Check the "DATA MONITOR" value of each DTC detected with the self-diagnosis function. Refer to 4WAS Main Control Unit.
Is each data the standard value?
YES - Check each harness connector pin terminal for disconnection.
NO - Replace 4WAS main control unit. Refer to Exploded View.




Special Repair Requirement

BEFORE REPLACING 4WAS MAIN CONTROL UNIT
- Record the self-diagnosis results (history).

CAUTION:
- Never erase the memory (history) of self-diagnosis results when replacing 4WAS main control unit after diagnosis.
- Erase the memory of the self-diagnosis results (record) after printing out or recording all the values of "DATA MONITOR".