B1779

DTC Troubleshooting: B1779

DTC B1779: HFL Switch or Voice Control 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 switch. Service and Repair

7. Disconnect HandsFreeLink control unit 28P connector.

8. Disconnect the HFL switch 7P connector.

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

10. Measure the voltage between HFL switch 7P connector terminal No. 4 and body ground.

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

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 switch 7P connector terminal No. 4.

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. 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 a short to power on the PUR wire.

NO - Go to step 15.

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

16. Check for continuity between HFL switch 7P connector terminal No. 5 and body ground.

Is there continuity?
YES - Replace the HandsFreeLink control unit. Service and Repair

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