B1779

DTC Troubleshooting: B1779

DTC B1779: HFL 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. Clear the DTCs with the HDS.

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

3. Check for DTCs with the HDS.

Is DTC B1779 indicated?
YES - Go to step 4.

NO - Intermittent failure, the system is OK at this time.


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

5. Do the HFL switch test. HFL Switch Test (With Navigation)

Is the switch OK?
YES - Go to step 6.

NO - Replace the cable reel subharness. Overhaul


6. Remove the glove box. Service and Repair

7. Disconnect the 28P connector from the HandsFreeLink control unit.

8. Disconnect the 20P connector from the cable reel subharness.

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

10. Check for voltage on the cable reel subharness 20P connector terminal No. 8.

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

NO - Go to step 11.


11. Check for continuity between the HandsFreeLink control unit 28P connector terminal No. 2 and cable reel subharness 20P connector terminal No. 8.

Is there continuity?
YES - Go to step 12.

NO - Repair open in the BLU wire between the switch, cable reel, and HandsFreeLink control unit.






12. Check for continuity between the cable reel subharness 20P connector terminal No. 9 and the audio unit connector B (32P) terminal No. 3.

Is there continuity?
YES - Check for loose or poor connections at the audio unit, HandsFreeLink control unit, and HFL switch. If the connections are OK, substitute a known-good HandsFreeLink control unit. If the problem is gone, replace the original control unit.

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