DTC Troubleshooting: B1776

DTC B1776: Microphone Input/Output Short to Ground/Open NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN system diagnosis test mode A.

1. Clear the DTCs with the HDS.

1. Turn the ignition switch OFF, and then back ON (II).

1. Check for DTCs with the HDS.

Is DTC B1776 indicated?

YES | - | Go to Step 4 .
NO | - | Intermittent failure, the system is OK at this time.■

1. Turn the ignition switch OFF.

1. Remove the roof console and the upper panel.

1. Disconnect the 28P connector from the roof console and the 22P connector from the hands free telephone control unit.

1. Check for continuity between body ground and the No. 9 and No. 10 terminals of the hands free telephone control unit 22P connector individually, then between terminals No. 8 and No. 9.

Is there continuity?

YES | - | Repair short in the wires between the hands free telephone control unit and the roof console.■
NO | - | Go to Step 8 .

1. Check for continuity between the following terminals of the hands free telephone control unit connector (22P) and the roof console connector 10P (LHD) or 12P (RHD).

   22P: | 10P (LHD): | 12P (RHD):
   --- | --- | ---
   No. 9 | No. 2 | No. 2
   No. 10 | No. 1 | No. 3

Is there continuity?

YES | - | Go to Step 9 .
NO | - | Repair open in the wires between the hands free telephone control unit and the roof console.■

1. Disconnect the 14P connector from the navigation unit.

RHD type
LHD type

1. Check for continuity between body ground and the No. 21 and No. 22 terminals of the hands free telephone control unit 22P connector, then between terminals No. 20 and No. 21.

Is there continuity?

YES | - | Repair short in the wires between the hands free telephone control unit and the navigation unit.■
NO | - | Go to Step 11 .

1. Check for continuity between following terminals of the hands free telephone control unit connector (22P) and the navigation unit connector C (14P).

   22P: | 14P:
   --- | ---
   No. 21 | No. 6
   No. 22 | No. 13

Is there continuity?

YES | - | Substitute a known-good hands free telephone control unit, then recheck. If the symptom goes away, replace the original hands free telephone control unit. If the symptom does not away, replace the faulty navigation unit.■
NO | - | Repair open the wires between the hands free telephone control unit and the navigation unit.■