DTC B1776

DTC B1776  : Microphone Input/Output Shorted to Ground

DTCs (Telematics System)

NOTE:  Check the connectors for poor connections or loose terminals.

1. Problem verification

   -1. Clear the DTCs with the HDS.

   -2. Turn the vehicle to the OFF (LOCK) mode.

   -3. Open the driver's door, and wait more than 1 minute.

   -4. Turn the vehicle to the ON mode.

   -5. Check for DTCs with the HDS.

   DTC Description	DTC
   B1776 Microphone Input/Output shorted to ground

   Is DTC B1776 indicated?

   YES 

   The failure is duplicated, go to step 2.

   NO 

   Intermittent failure, the system is OK at this time.

2. Determine possible failure area (MIC SIG line, others)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Open the driver's door, and wait more than 1 minute.

   -3. Disconnect the following connector.

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

   -4. Turn the vehicle to the ON mode.

   -5. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	Front HFL-ANC/active sound control microphone 8P connector: disconnected
   Test point 1	Front HFL-ANC/active sound control microphone 8P connector No. 2
   Test point 2	Body ground

   Is there about 8.0 V?

   YES 

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

   NO 

   Go to step 3.

3. Shorted wire check (MIC SIG line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Open the driver's door, and wait more than 1 minute.

   -3. Disconnect the following connector.

   Telematics control unit connector A (32P)

   -4. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Front HFL-ANC/active sound control microphone 8P connector: disconnected
   	Telematics control unit connector A (32P): disconnected
   Test point 1	Telematics control unit connector A (32P) No. 9
   Test point 2	Body ground

   Is there continuity?

   YES 

   There is a short to body ground in the wire. Replace the affected shielded harness.

   NO 

   The MIC SIG wire is not shorted to ground. Go to step 4.

4. Shorted wire check (MIC SIG line to another lines)

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

   Test condition	Vehicle OFF (LOCK) mode
   	Front HFL-ANC/active sound control microphone 8P connector: disconnected
   	Telematics control unit connector A (32P): disconnected
   Test point 1	Telematics control unit connector A (32P) No. 7
   Test point 2	Telematics control unit connector A (32P) No. 8

   Test point 1	Telematics control unit connector A (32P) No. 7
   Test point 2	Telematics control unit connector A (32P) No. 9

   Is there continuity between any of the terminals?

   YES 

   There is a short in the wires. Replace the affected shielded harness.

   NO 

   Replace the telematics control unit .