DTC B2C05: Sonar Control Module Power Supply

Outline of diagnosis: 

Voltage supply to the ignition power supply terminal was 16 V or more.

Time needed for diagnosis: 

5000 ms

Recovery conditions: 

Ignition switch OFF → ON

Wiring diagram: 

Reverse Automatic Braking system Ref. to WIRING SYSTEM>REVERSE AUTOMATIC BRAKING

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK CONNECTOR  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the RAB Control Module connector.
   3. Connect the disconnected connectors.
   4. Turn the ignition switch to ON.
   5. Read the DTC of [Reverse Automatic Braking] using the Subaru Select Monitor. Ref. to REVERSE AUTOMATIC BRAKING (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) 

   Is DTC B2C05 displayed? (Current code)

   Yes  : Go to  2.

   No  : Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

   NOTE:

   In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause. 

2. CHECK RAB CONTROL MODULE POWER SUPPLY CIRCUIT  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the RAB Control Module connector.
   3. Turn the ignition switch to ON.
   4. Using a tester, measure the voltage between the RAB Control Module connector and chassis ground.

      Connector & terminal 

      (L81) No. 1 (+) - Chassis ground (-):

      (L81) No. 13 (+) - Chassis ground (-):

   Is the voltage 16 V or less?

   Yes  : Replace the RAB Control Module. Ref. to REVERSE AUTOMATIC BRAKING>REVERSE AUTOMATIC BRAKING CONTROL MODULE

   No  : Check the harness between the RAB Control Module connector and power supply.