Inspection Procedure 3

Inspection Procedure 3: The illumination of the steering remote control switch 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 Audio Switch Illumination Circuit:

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

TROUBLESHOOTING HINTS
- Malfunction of steering remote control switch
- Malfunctions of combination meter
- Malfunction of the clock spring
- Damaged harness wires and connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. Check the combination meter.

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 Instrument Cluster/Carrier, Diagnosis)

STEP 2. Check steering remote control switch connector C-213 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is steering remote control switch connector C-213 in good condition?

YES: Go to Step 3.

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

STEP 3. Check the wiring harness between steering remote control switch connector C-213 (terminal 5) and ground.

Check the ground wire.

Q: Is the wiring harness between steering remote control switch connector C-213 (terminal 5) and 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-204 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are clock spring connectors C-202 and C-204 in good condition?

YES: Go to Step 5.

NO: Repair or replace the damaged component(s). Refer to 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 Air Bag Systems, 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 remote control switch connector C-213 (terminal 1) and clock spring connector C-202 (terminal 1).

Check the power supply lines.

Q: Is the wiring harness between steering remote control switch connector C-213 (terminal 1) 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-03 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is combination meter connector C-03 in good condition?

YES: Go to Step 8.

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

STEP 8. Check the wiring harness between combination meter connector C-03 (terminal 23) and clock spring connector C-204 (terminal 6).

Check the power supply lines.

Q: Is the wiring harness between combination meter connector C-03 (terminal 23) and clock spring connector C-204 (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 How to use Troubleshooting/inspection Service Points, How to Cope with Intermittent Malfunction).

NO: Replace the steering remote control switch.