Inspection Procedure 6: Steering wheel voice control switch illumination does not come on.


caution Before replacing the hands free ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.


TECHNICAL DESCRIPTION (COMMENT)



PROBABLE CAUSES



  • Malfunction of steering wheel voice control switch
  • Malfunction of the clock spring
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Check if the steering wheel audio remote control switch illuminates normally.

Q. Is the check result normal?
Go to Step 2.
Perform the troubleshooting for the illumination of steering wheel audio remote control switch.

STEP 2. Check the steering wheel voice control switch.

Q. Is the check result normal?
Go to Step 3.
Replace the steering wheel voice control switch.

STEP 3. Connector check: C-312 steering wheel voice control switch connector

Q. Is the check result normal?
Go to Step 4.
Repair the defective connector.

STEP 4. Check the wiring harness between C-312 steering wheel voice control switch connector terminal No.1 and body earth.

  • Check the earth wire for open circuit.

Q. Is the check result normal?
Go to Step 5.
Repair the wiring harness.

STEP 5. Connector check: C-310 clock spring connector

Q. Is the check result normal?
Go to Step 6.
Repair the defective connector.

STEP 6. Check the clock spring.
Check whether the clock spring is in good condition (Refer to GROUP 52B - Air bag module and clock spring ).

Q. Is the check result normal?
Go to Step 7.
Replace the clock spring.

STEP 7. Check the wiring harness between C-312 steering wheel voice control switch connector terminal No.4 and C-310 clock spring connector terminal No.1.

  • Check the wiring harness for open circuit and short circuit.

Q. Is the check result normal?
Go to Step 8.
Repair the wiring harness.

STEP 8. Retest the system
Check whether the illumination of the steering wheel voice control switch comes on normally.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the steering wheel voice control switch.