Inspection Procedure 6

Inspection Procedure 6: Steering Wheel Voice Control Switch Illumination Does Not Come On.

CAUTION: Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.

Steering Wheel Voice Control Switch Illumination Circuit:

TECHNICAL DESCRIPTION (COMMENT)
The power supply circuit to the steering wheel voice-control switch, the steering wheel voice control switch, the combination meter, or the clock spring may be defective.

TROUBLESHOOTING HINTS
- The steering wheel voice control switch may be defective.
- The combination meter may be defective.
- The clock spring may be defective.
- Damaged harness wires and connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Check the combination meter.

Check whether the combination meter works normally.

Q : Is the check result normal?

YES : Go to Step 2.

NO : Diagnose the combination meter. Diagnostic Trouble Code Descriptions

STEP 2. Check steering wheel voice control switch connector C-206 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q : Is steering wheel voice-control switch connector C-206 in good condition?

YES : Go to Step 3.

NO : Repair or replace the damaged component (Refer to General (Electrical), Harness Connector Inspection). The steering remote control switch should work normally.

STEP 3. Check the wiring harness between steering wheel voice control switch connector C-206 (terminal 1) and the ground.

- Check the ground wires for open circuit.

Q : Is the wiring harness between steering wheel voice-control switch connector C-206 (terminal 1) and the ground in good condition?

YES : Go to Step 4.

NO : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.

STEP 4. Check clock spring connectors C-202 and C-205 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q : Are clock spring connectors C-202 and C-205 in good condition?

YES : Go to Step 5.

NO : Repair or replace the damaged component (Refer to General (Electrical), Harness Connector Inspection). The steering remote control switch should work normally.

STEP 5. Check the clock spring.

Check whether the clock spring is in good condition (Refer to SRS -Driver's air bag module and clock spring).

Q : Is the check result normal?

YES : Go to Step 6.

NO : Replace the clock spring.

STEP 6. Check the wiring harness between steering wheel voice control switch connector C-206 (terminal 4) and clock spring connector C-202 (terminal 1).

- Check the communication lines for open circuit and short circuit.

Q : Is the wiring harness between steering wheel voice-control switch connector C-206 (terminal 4) and clock spring connector C-202 (terminal 1) in good condition?

YES : Go to Step 7.

NO : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.

STEP 7. Check combination meter connector C-04 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q : Is combination meter connector C-04 in good condition?

YES : Go to Step 8.

NO : Repair or replace the damaged component (Refer to General (Electrical), Harness Connector Inspection). The steering remote control switch should work normally.

STEP 8. Check the wiring harness between combination meter connector C-04 (terminal 23) and clock spring connector C-205 (terminal 6).

- Check the communication lines for open circuit and short circuit.

Q : Is the wiring harness between combination meter connector C-04 (terminal 23) and clock spring connector C-205 (terminal 6) in good condition?

YES : Go to Step 9.

NO : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.

STEP 9. Retest the system

Check whether the illumination of the steering remote control switch comes on normally.

Q : Doe the illumination of the steering remote control switch comes on normally?

YES : The trouble can be an intermittent malfunction (Refer to General (Body and Chassis), How to use Troubleshooting/inspection Service Points, How to Cope with Intermittent Malfunction).

NO : Replace the steering wheel voice control switch.