Inspection Procedure 2

Inspection Procedure 2: Steering Wheel Audio Remote Control Switch does not Function. [Vehicles with MMCS]

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 multivision display, or the clock spring may be defective.

TROUBLESHOOTING HINTS

- The steering wheel audio remote control switch may be defective.
- The multivision display 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 steering wheel audio remote control switch.

Remove the steering wheel audio remote control switch. Then check continuity between the switch terminals. (Refer to Component Tests and General Diagnostics.)





Q. Is the steering wheel audio remote control switch in good condition?

YES Go to Step 2.
NO Replace the steering wheel audio remote control switch.
STEP 2. Check clock spring connector C-202 and C-205 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Are clock spring connector C-202 and C-205 in good condition?

YES Go to Step 3.
NO Repair or replace the damaged component Harness Connector Inspection). The steering wheel audio remote control switch should work normally.
STEP 3. 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 4.
NO Replace the clock spring.
STEP 4. Check multivision display connector C-10 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is multivision display connector C-10 in good condition?

YES Go to Step 5.
NO Repair or replace the damaged component Harness Connector Inspection). The steering wheel audio remote control switch should work normally.
STEP 5. Check the wiring harness between multivision display connector C-10 (terminal 43, 59) and clock spring connector C-205 (terminal 2, 3).

NOTE:
Also check intermediate connector C-108, C-32 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-108, C-32 is damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection.

- Check the communication lines for open and short circuit.

Q. Is the wiring harness between multivision display connector C-10 (terminal 43, 59) and clock spring connector C-205 (terminal 2, 3) in good condition?

YES Go to Step 6.
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 6. 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 7.
NO Repair or replace the damaged component Harness Connector Inspection). The steering wheel audio remote control switch should work normally.
STEP 7. Check the wiring harness between steering wheel audio remote control switch connector C-213 (terminal 2, 4) and clock spring connector C-202 (terminal 5, 4).

- Check the communication lines for open and short circuit.

Q. Is the wiring harness between steering wheel audio remote control switch connector C-213 (terminal 2, 4) and clock spring connector C-202 (terminal 5, 4) 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. Retest the system

Check whether you can operate the multivision display by using the steering remote control.

Q. Is the check result normal?

YES The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).
NO Replace the multivision display.