DTC B1775: Microphone In/Out Open or Shorted to Power (2016-18)

DTC (Telematics System)

1. Problem verification:

   Clear the DTCs with the HDS.

   Clear DTCs

   - 2. Press the engine start/stop button to select the OFF mode and then select the ON mode.

   - 3. Check for DTCs with the HDS.

   DTC Description	DTC
   B1775 Microphone In/Out Open or Shorted to Power

   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):

   Press the engine start/stop button to select the OFF mode.

   - 2. Disconnect the following connectors.

   Telematics control unit connector A (36P)

   Front HFL-ANC/active sound control microphone 8P connector

   - 3. Press the engine start/stop button to select the ON mode.

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

   Test condition	ON mode
   	Telematics control unit connector A (36P): disconnected
   	Front HFL-ANC/active sound control microphone 8P connector: disconnected
   Test circuit	MIC+
   Test point 1	Front HFL-ANC/active sound control microphone 8P connector No. 2 (WHT)
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there about 8.0 V or more?

   YES 

   There is a short to power in the wire between the telematics control unit and the front HFL-ANC/active sound control microphone. Replace the affected shielded harness.

   NO 

   The MIC+ wire is not shorted to power. Go to step 3.

3. Determine possible failure area (MIC+ line, others):

   Press the engine start/stop button to select the OFF mode.

   - 2. Reconnect telematics control unit connector A (36P).

   - 3. Press the engine start/stop button to select the ON mode.

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

   Test condition	ON mode
   	Front HFL-ANC/active sound control microphone 8P connector: disconnected
   Test circuit	MIC+
   Test point 1	Front HFL-ANC/active sound control microphone 8P connector No. 2 (WHT)
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there about 8.0 V?

   YES 

   Go to step 5.

   NO 

   Go to step 4.

4. Open wire check (MIC+ line):

   Measure the voltage between test points 1 and 2.

   Test condition	ON mode
   	Front HFL-ANC/active sound control microphone 8P connector: disconnected
   Test circuit	MIC+
   Test point 1	Telematics control unit connector A (36P) No. 4 (WHT)
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there about 8.0 V?

   YES 

   There is an open in the wire between the telematics control unit and the front HFL-ANC/active sound control microphone. Replace the affected shielded harness.

   NO 

   Replace the telematics control unit .

5. Open wire check (MIC GND line):

   Press the engine start/stop button to select the OFF mode.

   - 2. Disconnect the following connector.

   Telematics control unit connector A (36P)

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

   Test condition	OFF mode
   	Front HFL-ANC/active sound control microphone 8P connector: disconnected
   	Telematics control unit connector A (36P): disconnected
   Test circuit	MIC GND
   Test point 1	Telematics control unit connector A (36P) No. 3 (RED)
   Test point 2	Front HFL-ANC/active sound control microphone 8P connector No. 1 (RED)

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The MIC GND wire is OK. Go to step 6.

   NO 

   Repair an open in the wire between the telematics control unit and the front HFL-ANC/active sound control microphone.

6. Shorted wire check (HFT-NAVI MIC+ line to power):

   Disconnect the following connector.

   Audio-navigation unit connector F (18P)

   - 2. Press the engine start/stop button to select the ON mode.

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

   Test condition	ON mode
   	Front HFL-ANC/active sound control microphone 8P connector: disconnected
   	Telematics control unit connector A (36P): disconnected
   	Audio-navigation unit connector F (18P): disconnected

   Test circuit	HFT-NAVI MIC+
   Test point 1	Audio-navigation unit connector F (18P) No. 13 (BLU)
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there about 8.0 V or more?

   YES 

   There is a short to power in the wire between the telematics control unit and the audio-navigation unit. Replace the affected shielded harness.

   NO 

   The HFT-NAVI MIC+ wire is not shorted to power. Go to step 7.

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

   Press the engine start/stop button to select the OFF mode.

   - 2. Reconnect telematics control unit connector A (36P).

   - 3. Reconnect the front HFL-ANC/active sound control microphone 8P connector.

   - 4. Clear the DTCs with the HDS.

   Clear DTCs

   - 5. Press the engine start/stop button to select the OFF mode and then select the ON mode.

   - 6. Check for DTCs with the HDS.

   DTC Description	DTC
   B1775 Microphone In/Out Open or Shorted to Power

   Is DTC B1775 indicated?

   YES 

   Go to step 8.

   NO 

   Replace the audio-navigation unit .

8. Front HFL-ANC/active sound control microphone check (substitution):

   Press the engine start/stop button to select the OFF mode.

   - 2. Substitute a known-good front HFL-ANC/active sound control microphone .

   - 3. Clear the DTCs with the HDS.

   Clear DTCs

   - 4. Press the engine start/stop button to select the OFF mode and then select the ON mode.

   - 5. Check for DTCs with the HDS.

   DTC Description	DTC
   B1775 Microphone Input/Output open or shorted to power

   Is DTC B1775 indicated?

   YES 

   Replace the telematics control unit .

   NO 

   Replace the original front HFL-ANC/active sound control microphone.