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

STEP 1. Using scan tool MB991958, check data list.

Check whether the service data below are normal.

(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III) Reading and Clearing Diagnostic Trouble Codes."

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

(3)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 steering wheel audio remote control 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-304 and C-312 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Are clock spring connector C-304 and C-312 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. Testing and 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-103 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is radio and CD player connector C-103 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-103 (terminal 22, 32) and clock spring connector C-312 (terminal 2, 3).

- Check the communication lines for open and short circuit.

Q. Is the wiring harness between radio and CD player connector C-103 (terminal 22, 32) and clock spring connector C-312 (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-301 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is steering wheel audio remote control switch connector C-301 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-301 (terminal 2, 4) and clock spring connector C-304 (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-301 (terminal 2, 4) and clock spring connector C-304 (terminal 2, 3) 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.