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DTC B278D: Id Code Box Recognition Judgment Abnormal: Trouble Symptom

WARNING: This page is about a different car, the 2014 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

Engine will not start.

CAUTION: For replacement procedure of keyless access control module, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER".
DTC PROCEDURE

Step Check Yes No
1 CHECK DTC. 
  1. Turn the ignition switch to OFF.
  2. Using the Subaru Select Monitor, clear the keyless access system memory.
  3. Turn the ignition switch to OFF → ON.
  4. Use the Subaru Select Monitor and read DTCs.
 Is B278D displayed? Go to step 2  . System is normal. It is possible that temporary poor contact occurs.
2 CHECK HARNESS. 
  1. Disconnect the keyless access CM connector.
  2. Measure the resistance between keyless access CM 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? Replace the keyless access CM. < Ref. to REMOVAL , Keyless Access CM. > Repair or replace the short circuit of the harness.
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