Inspection Procedure 2: Steering Wheel Remote Control Switch Illumination Does Not Come On: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe

1. STEP 1. Check the steering wheel remote control switch. 

   Check the steering wheel remote control switch (Refer to STEERING WHEEL AUDIO REMOTE CONTROL SWITCH CHECK  ).

   Q: Is the check result normal? 

   • YES:  Go to Step 2.
   • NO:  Replace the steering wheel remote control switch.
2. STEP 2. Resistance measurement at steering wheel remote control switch connector (ground terminal) 
   1. Disconnect the connector, and measure at the wiring harness side.
   2. Measure the resistance between the steering wheel remote control switch connector (ground terminal) and ground.

      OK: The resistance should be 2 ohms or less 

   Q: Is the check result normal? 

   • YES:  Go to Step  4.
   • NO:  Go to Step 3.
3. STEP 3. Check of open circuit in ground line between steering wheel remote control switch connector and ground 

   Q: Is the check result normal? 

   • YES:  Intermittent malfunction is suspected (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
   • NO:  Repair the connector(s) or wiring harness.
4. STEP 4. Check the clock spring. 

   Check whether the clock spring is in good condition. Refer to DRIVER'S AIR BAG MODULE AND CLOCK SPRING .

   Q: Is the check result normal? 

   • YES:  Go to Step 5.
   • NO:  Replace the clock spring.
5. STEP 5. Check of short to power supply, short to ground, and open circuit in ILL+ line between combination meter connector and steering wheel remote control switch connector 

   Q: Is the check result normal? 

   • YES:  Go to Step 6.
   • NO:  Repair the connector(s) or wiring harness.
6. STEP 6. Retest the system 

   Check whether the illumination of the steering wheel remote control switch comes on normally.

   Q: Is the check result normal? 

   • YES:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
   • NO:  Replace the combination meter.