Inspection Procedure 3

Inspection Procedure 3: Steering wheel audio remote 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.














TECHNICAL DESCRIPTION (COMMENT)

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

TROUBLESHOOTING HINTS

- The steering wheel audio remote control switch 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 metre.

Check whether the combination meter works normally.

Q. Does the combination meter operate normally?

YES Go to Step 2.
NO Diagnose the combination meter (Refer to Combination Meter).
STEP 2. Check the steering wheel voice control switch.

(Refer to Component Tests and General Diagnostics).

Q. Is the check result normal?

YES Go to Step 3.
NO Replace the clock spring.
STEP 3. Check steering wheel audio remote control switch connector C-213 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is steering wheel audio remote control switch connector C-213 in good condition?

YES Go to Step 4.
NO Repair or replace the damaged component Harness Connector Inspection).
STEP 4. Check the wiring harness between steering wheel audio remote control switch connector C-213 (terminal 5) and ground.

- Check the ground wire for open circuit.

Q. Is the wiring harness between steering wheel audio remote control switch connector C-213 (terminal 5) and ground in good condition?

YES Go to Step 5.
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 5. 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 6.
NO Repair or replace the damaged component Harness Connector Inspection).
STEP 6. Check the clock spring.

Check whether the clock spring is in good condition Testing and Inspection).

Q. Is the check result normal?

YES Go to Step 7.
NO Replace the clock spring.
STEP 7. Check the wiring harness between steering wheel audio remote control switch connector C-213 (terminal 1) and clock spring connector C-202 (terminal 1).

- Check the power supply line for open circuit and short circuit.

Q. Is the wiring harness between steering wheel audio remote control switch connector C-213 (terminal 1) and clock spring connector C-202 (terminal 1) in good condition?

YES Go to Step 8.
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 8. 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 9.
NO Repair or replace the damaged component Harness Connector Inspection).
STEP 9. Check the wiring harness between combination meter connector C-04 (terminal 23) and clock spring connector C-205 (terminal 6).

- Check the power supply line 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 10.

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 10. Retest the system

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

Q. Doe the illumination of the steering wheel audio remote control switch comes on normally?

YES The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).
NO Replace the steering wheel audio remote control switch.