B1780

DTC Troubleshooting: B1780

DTC B1780: HFL Switch (HFL TALK/HFL BACK Buttons) Circuit 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. 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, from lock to lock, several times.

4. Check for DTCs with the HDS.

Is DTC B1780 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/Replacement

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

NO - Replace the HFL switch. HFL Switch Test/Replacement


7. Remove the glove box. Glove Box Removal/Installation

8. Disconnect the HandsFreeLink control unit 28P connector.

9. Disconnect the HFL switch 6P connector.

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

11. Check for continuity between the HandsFreeLink control unit 28P connector terminal No. 2 and body ground.

Is there continuity?
YES - Repair short in the wire.

NO - Substitute a known-good HandsFreeLink control unit, Service and Repair and recheck. If the symptom/indication goes away, replace the original HandsFreeLink control unit. Service and Repair