B1780

DTC Troubleshooting: B1780

DTC B1780: HandsFreeLink steering wheel switch line short

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in 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 engine, and turn the steering wheel 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.

Is the switch OK?

YES -

Go to step 7.

NO -

Replace the HFL-navigation voice control switch Service and Repair.�

7. Disconnect the HandsFreeLink control unit 28P connector.

8. Disconnect the HFL-navigation voice control switch 5P connector, then reconnect the cable reel subharness 20P 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, the cable reel, and the HFL-navigation voice control switch. If the wire is OK, substitute a known-good cable reel Service and Repair, and recheck. If the symptom/indication goes away, replace the original cable reel Service and Repair.�

NO -

Replace the HandsFreeLink control unit Service and Repair.�