B1779

DTC Troubleshooting: B1779

DTC B1779:

HFL Switch (HFL TALK/HFL BACK Buttons) Circuit Open/Short to Power

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN system diagnosis test mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.

1. Connect the HDS to the DLC Initial Inspection and Diagnostic Overview.

2. Clear the DTCs with the HDS.

3. Turn the ignition switch to LOCK (0), then start the vehicle and turn the steering wheel back and forth several times.

4. Check for DTCs with the HDS.

Is DTC B1779 indicated?

YES -

Go to step 5.

NO -

Intermittent failure, the system is OK at this time.�

5. Turn the ignition switch to LOCK (0).

6. Do the HFL switch test HFL Switch Test.

Is the switch OK?

YES -

Go to step 7.

NO -

Replace the HFL-voice control switch HFL Switch Removal/Installation.�

7. Disconnect the HandsFreeLink control unit 28P connector.

8. Disconnect the HFL-voice control switch 5P connector.

9. Turn the ignition switch to ON (II).

10. Measure the voltage between HFL-voice control switch 5P connector terminal No. 3 and body ground.





Is there voltage?

YES -

Repair a short to power in the wire between the HandsFreeLink control unit and the HFL-voice control switch.�

NO -

Go to step 11.

11. Turn the ignition switch to LOCK (0).

12. Check for continuity between HandsFreeLink control unit 28P connector terminal No. 2 and HFL-voice control switch 5P connector terminal No. 3.





Is there continuity?

YES -

Go to step 13.

NO -

Repair an open in the wire between the switch, the cable reel, and the HandsFreeLink control unit.�

13. Check for continuity between audio unit connector F (20P) terminal No. 6 and HFL-voice control switch 5P connector terminal No. 2.





Is there continuity?

YES -

Check for loose or poor connections at the audio unit, HandsFreeLink control unit and HFL-voice control switch. If the connections are OK, substitute a known-good HandsFreeLink control unit Service and Repair. If the problem is gone, replace the original HandsFreeLink control unit.�

NO -

Repair an open in the wire between the switch, the cable reel, and the audio unit.�