B1779

DTC Troubleshooting: B1779

DTC B1779: HFL Switch or Voice Control Switch (HFL TALK/HFL BACK Buttons) Circuit Open/Short

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.

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 (With HandsFreeLink)

Is the switch OK?
YES - Go to step 7.

NO - Replace the HFL-voice control switch. Overhaul


7. Remove the driver's dashboard lower cover. Drivers Dashboard Lower Cover Removal/Installation

8. Disconnect HandsFreeLink control unit 28P connector.

9. Disconnect HFL-voice control switch 5P connector.

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

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

Is there voltage?
YES - Repair short to power on the BLU wire.

NO - Go to step 12.






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 open in the BLU wire between the switch, the cable reel, and the HandsFreeLink control unit.






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

14. Measure the voltage between HandsFreeLink control unit 28P connector terminal No. 2 and body ground.

Is there voltage?
YES - Repair short to body ground in the wire between the HandsFreeLink control unit and the HFL-voice control switch.

NO - Go to step 15.






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

16. Check for continuity between HFL-voice control switch 5P connector terminal No. 4 and body ground.

Is there continuity?
YES - Replace the HandsFreeLink control unit. HandsFreeLink Control Unit Input Test/Replacement (With HandsFreeLink)

NO - Repair open in the wire between the HFL-voice control switch, cable reel, and the audio unit.