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 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.

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





Is there continuity?

YES -

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

NO -

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.�