DTC B278D: Id Code Box Judgment Circuit

DTC detecting condition:

When the evaluation of the ID code box setting circuit via the hard wire is judged as none, ID code box communication is received. (at new registration)

Trouble symptom:

Initial registration for the access key is not possible.

CAUTION: For replacement procedure of keyless access Control Module, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.

Wiring diagram:

NOTE: For the coupling connector, refer to "WIRING SYSTEM".

Keyless access with push button start system Ref. to WIRING DIAGRAM , Keyless Access With Push Button Start System.

Fig 1: ID Code Box Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK DTC. Turn the ignition switch to OFF. Using the Subaru Select Monitor, clear the memory of «Keyless Access with Push Button Start». Ref. to CLEAR MEMORY MODE Turn the ignition switch to OFF → ON. Read the DTC using Subaru Select Monitor. Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC)	Is DTC B278D displayed?	Go to step 2	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. Disconnect the keyless access Control Module connector. Measure the resistance between keyless access Control Module connector and chassis ground. Connector & terminal (i241) No. 23 - Chassis ground:	Is the resistance 10 kΩ or more?	Replace the keyless access Control Module. Ref. to KEYLESS ACCESS CONTROL MODULE	Repair or replace the short circuit of the harness.