DTC B2C25: RR Sonar Harness

Outline of diagnosis: 

Sonar sensor (right corner) harness is open.

Time needed for diagnosis: 

100 ms

Recovery conditions: 

Ignition switch OFF → ON

Wiring diagram: 

Reverse Automatic Braking Refer 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 sonar sensor (right corner) connector (L111).
   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. Refer to REVERSE AUTOMATIC BRAKING (DIAGNOSTICS)>Diagnostic Trouble Code (DTC) .

      Is DTC B2C25 displayed? (Current malfunction)

      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 HARNESS BETWEEN SONAR SENSOR CONNECTOR AND RAB Control Module CONNECTOR. (OPEN CIRCUIT)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the sonar sensor (right corner) connector (L111) and the RAB Control Module connector (L81).
   3. Using a tester, measure resistance of the harness between the sonar sensor (right corner) connector (L111) and RAB Control Module connector (L81).

      Connector & terminal 

      (L81) No. 4 - (L111) No. 2:

      Is the resistance less than 10 Ω?

      Yes  : Go to  3.

      No  : Repair or replace the open circuit in the harness between the sonar sensor (right corner) connector (L111) and the RAB Control Module connector (L81).

3. CHECK SONAR SENSOR  .
   1. Switch the sonar sensor (right corner) and sonar sensor (right inner).
   2. Connect the disconnected connectors.
   3. Turn the ignition switch to ON.
   4. Read the DTC of [Reverse Automatic Braking] using the Subaru Select Monitor. Refer to REVERSE AUTOMATIC BRAKING (DIAGNOSTICS)>Diagnostic Trouble Code (DTC) .

      Is DTC B2C25 displayed? (Current malfunction)

      Yes  : Replace the RAB Control Module. Refer to REVERSE AUTOMATIC BRAKING>REVERSE AUTOMATIC BRAKING Control Module .

      No  : Replace the sensor installed as a sonar sensor (right corner). Refer to Reverse Automatic Braking>Sensor and Harness .