B1779

DTC Troubleshooting: B1779

DTC B1779:

HandsFreeLink steering wheel switch failure

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 engine, and turn the steering wheel from lock to lock 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.

Is the switch OK?

YES -

Go to step 6.

NO -

Replace the HFL-voice control switch Overhaul.�

6. Disconnect the HandsFreeLink control unit 28P connector.

7. Disconnect the HFL-voice control switch 5P connector.

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

9. Measure the voltage between Handsfreelink control unit 28P connector terminal No. 2 and body ground.





Is there battery voltage?

YES -

Go to step 10.

NO -

Go to step 14.

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

11. Disconnect the dashboard wire harness 20P connector from the cable reel.

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

13. Measure the voltage between HandsFreeLink control unit 28P connector terminal No. 2 and body ground.





Is there battery voltage?

YES -

Repair a short to power on the WHT wire between the HandsFreeLink control unit and the cable reel.�

NO -

Go to step 14.

14. Check for continuity between HandsFreeLink control unit 28P connector terminal No. 2 and HFL-voice control switch 5P connector terminal No. 3.





Is there continuity?

YES -

Go to step 15.

NO -

Substitute a known-good cable reel Service and Repair, and retest. If there is continuity, replace the original cable reel Service and Repair. If there is still no continuity, repair an open in the WHT wire between the HFL-voice control switch, the cable reel, and the HandsFreeLink control unit.�

15. 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 -

Go to step 16.

16. Check for continuity between audio unit connector A (24P) terminal No. 5 and HFL-voice control switch 5P connector terminal No. 4.





Is there continuity?

YES -

Replace the HandsFreeLink control unit Service and Repair.�

NO -

Repair an open in the wire between the HFL-voice control switch, the cable reel, and the audio unit.�