Without Moonroof

Control System DTCs

DTC Troubleshooting: B1775

DTC B1775 : Microphone input/output shorted to power or open (without moonroof)

NOTE:
* Check the vehicle battery condition first Battery Test.
* Check the connectors for poor connections or loose terminals.

1. Problem verification:

Problem verification
-1. Check for HFL DTCs How To Troubleshoot The HandsFreeLink System.

Is DTC B1775 indicated?
-YES- The failure is duplicated, go to step 2.
-NO- Intermittent failure, the system is OK at this time.

2. Shorted wire check (MIC+ line to power):

Shorted wire check (MIC+ line to power)
-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connectors.





-3. Turn the ignition switch to ON (II).

-4. Measure the voltage between test points 1 and 2.









Is there voltage?
-YES- There is a short to power in the wire between the HandsFreeLink control unit and the HFL microphone. Replace the affected shielded harness.
-NO- Go to step 3.

3. Open wire check (MIC+ line, MIC- line):

Open wire check (MIC+ line, MIC- line)
-1. Turn the ignition switch to LOCK (0).

-2. Check for continuity between test points 1 and 2.














Is there continuity?
-YES- Go to step 5.
-YES- Go to step 4.
-NO- There is an open in the wire(s) between the HandsFreeLink control unit and the HFL microphone. Replace the affected shielded harness.

4. HandsFreeLink control unit check:

HandsFreeLink control unit check
-1. Substitute a known-good HFL microphone HFL Microphone Removal and Installation (With Moonroof), and recheck.

Does the symptom/indication go away?
-YES- Replace the original HFL microphone.
-NO- Replace the HandsFreeLink control unit Service and Repair.

5. Shorted wire check (TELEM_SIG+ line to power):

Shorted wire check (TELEM_SIG+ line to power)
-1. Disconnect the following connector.





-2. Turn the ignition switch to ON (II).

-3. Measure the voltage between test points 1 and 2.









Is there voltage?
-YES- There is a short to power in the wire between the HandsFreeLink control unit and the audio-navigation unit. Replace the affected shielded harness.
-NO- Go to step 6.

6. Determine possible failure area (audio-navigation unit, others):

Determine possible failure area (audio-navigation unit, others)
-1. Turn the ignition switch to LOCK (0).

-2. Reconnect the HandsFreeLink control unit 32P connector and the HFL microphone 10P connector.

-3. Turn the ignition switch to ON (II).

-4. Do the HFL Self-Diagnostic Function HandsFreeLink System Self-Diagnostic Function.

Do you hear, "The HFT is OK"?
-YES- Replace the audio-navigation unit Audio-Navigation Unit Removal and Installation.
-NO- Go to step 7.

7. HandsFreeLink control unit check:

HandsFreeLink control unit check
-1. Turn the ignition switch to LOCK (0).

-2. Substitute a known-good HFL microphone HFL Microphone Removal and Installation (With Moonroof), and recheck.

Does the symptom/indication go away?
-YES- Replace the original HFL microphone.
-NO- Replace the HandsFreeLink control unit HFL-Navigation Microphone Removal and Installation.