Except For Co And C5

Diagnosis start condition: 

• Battery voltage is 10 V or more.
• The remote engine starter was not used to start the engine.

DTC detecting condition: 

Reference code incompatibility between body integrated unit and ECM

Trouble symptom: 

• Engine will not start.
• The security indicator illuminates.

1. CONFIRM NUMBER OF REGISTERED IMMOBILIZER KEY  .

   Confirm the number of registered immobilizer key. Refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.

   Is the number of registration 0?

   Yes  : Go to  2 .

   No  : Go to  4 .

2. CHECK GROUNDING POINT  .

   Check the grounding point of the engine ground and chassis ground.

   Is there any looseness? Are there any foreign matters caught on the ground or contact surface? Are there any oil-soiled areas?

   Yes  : Remove the foreign matters, and tighten to the specified torque. Then start the engine, and check that the fault was removed. Read the DTC Ref. to Immobilizer (Diagnostics)>Diagnostic Trouble Code (DTC) ., and when DTC B1571 is still displayed. Go to  3 .

   No  : Go to  3 .

3. PERFORM IMMOBILIZER SYSTEM REGISTRATION  .

   Register the immobilizer system. Refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.

   Is registration complete?

   Yes  : Finish the diagnosis.

   No  : Go to  4 .

4. PERFORM ECM REGISTRATION  .

   Perform ECM registration. Refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.

   Is registration complete?

   Yes  : Finish the diagnosis.

   No  : Go to  5 .

5. CHECK DTC  .
   1. Turn the ignition switch to ON.
   2. Using the Subaru Select Monitor, perform the clear memory of [Engine]. Ref. to COMMON (DIAG)>CLEAR MEMORY .
   3. Read the DTC of [Engine Control System] using the Subaru Select Monitor. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTIC TROUBLE CODE (DTC) .

      Are DTCs other than DTC B1571 displayed? (Current malfunction)

      Yes  : Perform the diagnosis for DTC other than DTC B1571.

      No  : Go to  6 .

6. PERFORM ECM REGISTRATION  .
   1. Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) .
   2. Perform ECM registration. Refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.

      Is registration complete?

      Yes  : Finish the diagnosis.

      No  : Refer to "Correspondence table when registration is not possible" in the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume. If the registration still does not work properly, replace the body integrated unit. Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT .