Inspection Procedure 1

Inspection Procedure 1: steering wheel audio remote control switch does not function. [vehicles with radio and CD player]

CAUTION:
Before replacing the radio and CD player or steering wheel audio remote control switch , 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 radio and CD player, or the clock spring may be defective.

TROUBLESHOOTING HINTS

- Malfunction of steering wheel audio remote control switch

- Malfunctions of radio and CD player

- 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. Using scan tool MB991958, check data list.

Check whether the service data below are normal.

(1)Turn the ignition switch to "ON" position.

(2)Operate each switch of the steering wheel audio remote control. Check whether the normal conditions listed below are displayed. (Refer to Data List Reference Table.)





OK: Normal condition is displayed.


Q. Is the check result normal?

YES Replace the radio and CD player.
NO Go to Step 2.
STEP 2. Check the remote controlled radio switch.









Remove the remote controlled radio switch. Then check continuity between the steering wheel audio remote control switch terminals.





Q. Is the remote controlled radio switch in good condition?

YES Go to Step 3.

NO Replace the steering wheel audio remote control switch.

STEP 3. Check clock spring connector C-202 and C-204 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Are clock spring connector C-202 and C-204 in good condition?

YES Go to Step 4.
NO Repair or replace the damaged component(s). Harness Connector Inspection.
STEP 4. Check the clock spring.

Check whether the clock spring is in good condition. Inspection.

Q. Is the check result normal?

YES Go to Step 5.
NO Replace the clock spring.
STEP 5. Check radio and CD player connector C-16 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is radio and CD player connector C-16 in good condition?

YES Go to Step 6.
NO Repair or replace the damaged component(s). Harness Connector Inspection.
STEP 6. Check the wiring harness between radio and CD player connector C-16 (terminal 22, 32) and clock spring connector C-204 (terminal 2, 3).

- Check the communication lines for open and short circuit.

Q. Is the wiring harness between radio and CD player connector C-16 (terminal 22, 32) and clock spring connector C-204 (terminal 2, 3) 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 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 8.
NO Repair or replace the damaged component(s). Harness Connector Inspection. The steering wheel audio remote control switch should work normally.
STEP 8. 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 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 you can operate the radio and CD player by using the steering wheel audio remote control switch.

Q. Is the check result normal?

YES The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).
NO Replace the radio and CD player.