Inspection Procedure 2: The Illumination of the Steering Wheel Remote Control Switch does not Come On.


caution Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.








TECHNICAL DESCRIPTION (COMMENT)


The power supply circuit to the steering wheel remote control switch, the steering wheel remote control switch, the combination meter, or the clock spring may be defective.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. Check the combination meter.


Check whether the combination meter works normally.

Q. Does the combination meter operate normally?
Go to Step 2.
Diagnose the combination meter (Refer to Combination Meter - Troubleshooting ).

STEP 2. Connector check: D-312 steering wheel remote control switch connector

Q. Is the check result normal?
Go to Step 3.
Repair the defective connector.

STEP 3. Check the wiring harness between D-312 steering wheel remote control switch connector terminal No.5 and body earth.

  • Check the earth wire.

Q. Is the check result normal?
Go to Step 4.
Repair the wiring harness.

STEP 4. Connector check: D-302 and D-305 clock spring connectors

Q. Is the check result normal?
Go to Step 5.
Repair the defective connector.

STEP 5. Check the clock spring.
Check whether the clock spring is in good condition (Refer to GROUP 52B - Air bag module and clock spring ).

Q. Is the check result normal?
Go to Step 6.
Replace the clock spring.

STEP 6. Check the wiring harness between D-312 steering wheel remote control switch connector terminal No.4 and D-302 clock spring connector terminal No.1.

  • Check the power supply lines.

Q. Is the check result normal?
Go to Step 7.
Repair the wiring harness.

STEP 7. Connector check: D-241 intermediate connector

Q. Is the check result normal?
Go to Step 8.
Repair the defective connector.

STEP 8. Check the wiring harness between D-241 intermediate connector terminal No.12 and D-305 clock spring connector terminal No.6.

  • Check the power supply lines.

Q. Is the check result normal?

    Go to Step 9.
Repair the wiring harness.

STEP 9. Retest the system
Check whether the illumination of the steering wheel remote control switch comes on normally.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the steering wheel remote control switch.