DTC B1780: HandsFreeLink Steering Wheel Short to Ground or Switch Failure

WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN system diagnosis test mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

Connect the HDS to the DLC (see GENERAL TROUBLESHOOTING INFORMATION ).
Clear the DTCs with the HDS.
Turn the ignition switch to LOCK (0), then start the vehicle, and turn the steering wheel back and forth several times.
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.
Turn the ignition switch to LOCK (0).
Do the HFL switch test (see HFL SWITCH TEST ).
Is the switch OK?

YES -Go to Step 7.

NO -Replace the HFL-navigation voice control switch (see VOICE CONTROL SWITCH TEST ).
Disconnect the HandsFreeLink control unit 28P connector.
Disconnect the HFL-navigation voice control switch 5P connector, then connect the cable reel 20P connector.
Check for continuity between HandsFreeLink control unit 28P connector terminal No. 2 and body ground.

Fig 1: Checking Continuity Between HandsFreeLink Control Unit 28P Connector Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

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 (see CABLE REEL REPLACEMENT ), and recheck. If the symptom/indication goes away, replace the original cable reel.

NO -Replace the HandsFreeLink control unit (see CONTROL UNIT INPUT TEST/REPLACEMENT ).