Inspection Procedure 2: Steering Wheel Audio Remote Control Switch Does Not Function - Vehicles With MMCS: Diagnosis

WARNING: This page is about a different variant/trim than selected.

Required Special Tools:

MB991223: Harness Set
MB992006: Extra Fine Probe

STEP 1. Check the remote controlled radio switch.
Check the steering wheel audio remote control switch (Refer to STEERING WHEEL AUDIO REMOTE CONTROL SWITCH INSPECTION ).

Q: Is the remote controlled radio switch in good condition?
- YES: Go to Step 2.
- NO: Replace the remote controlled radio switch.
STEP 2. Check clock spring connector C-204 and C-205 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are clock spring connector C-204 and C-205 in good condition?
- YES: Go to Step 3.
- NO: Repair or replace the damaged component (Refer to 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 (Refer to CLOCK SPRING < Except RALLIART > or >> C << STEERING WHEEL ASSEMBLY/DRIVER'S AIR BAG MODULE ASSEMBLY INSTALLATION < RALLIART >).

Q: Is the check result normal?
- YES: Go to Step 4.
- NO: Replace the clock spring.
STEP 4. Check multivision display connector C-12 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is multivision display connector C-12 in good condition?
- YES: Go to Step 5.
- NO: Repair or replace the damaged component (Refer to HARNESS CONNECTOR INSPECTION ). The steering wheel audio remote control switch should work normally.
STEP 5. Check the wiring harness between multivision display connector C-12 (terminal 53, 69) and clock spring connector C-205 (terminal 2, 3).
- Check the communication lines for open and short circuit.
NOTE: Also check intermediate connector C-105 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-105 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .

Q: Is the wiring harness between multivision display connector C-12 (terminal 53, 69) 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-202 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is steering wheel audio remote control switch connector C-202 in good condition?
- YES: Go to Step 7.
- NO: Repair or replace the damaged component (Refer to 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-202 (terminal 2, 4) and clock spring connector C-204 (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-202 (terminal 2, 4) and clock spring connector C-204 (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 wheel audio remote control.

Q: Is the check result normal?
- YES: The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
- NO: Replace the multivision display.