DTC B278D: Id Code Box Judgment Circuit

DTC detecting condition: 

When ID code box setting is set to OFF, ID code box LIN signal is received.

Trouble symptom: 

Engine will not start.

1. CHECK DTC  .
   1. Turn the ignition switch to OFF.
   2. Using the Subaru Select Monitor, clear the memory. Ref. to KEYLESS ACCESS WITH PUSH BUTTON START(DIAGNOSTICS)>Clear memory .
   3. Turn the ignition switch to OFF → ON.
   4. Read the DTC using Subaru Select Monitor. Ref. to KEYLESS ACCESS WITH PUSH BUTTON START(DIAGNOSTICS)>Diagnostic Trouble Code (DTC) .

   Is B278D displayed?

   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 (GROUND SHORT CIRCUIT)  .
   1. Disconnect the keyless access Control Module connector.
   2. Measure the resistance between keyless access Control Module connector and chassis ground.

      Connector & terminal

      (B573) No. 15 - Chassis ground:

   Is the resistance 10 kΩ or more? Or is the terminal (B573) No. 15 disconnected?

   Yes: Replace the keyless access Control Module. Ref. to SECURITY AND LOCKS>Keyless Access Control Module>REMOVAL .

   No: Repair or replace the short circuit of the harness.