Malfunction Indicator Light Remains Blinking

Diagnosis: 

The delivery (test) mode fuse circuit is short-circuited to ground.

Trouble symptom: 

Malfunction indicator light blinks when delivery (test) mode fuse is not connected.

Wiring diagram: 

Engine Electrical System Ref. to WIRING SYSTEM>Engine Electrical System>WIRING DIAGRAM

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK DELIVERY (TEST) MODE FUSE. 
   1. Check the delivery (test) mode fuse is removed.
   2. Turn the ignition switch to ON.

   Does the malfunction indicator light blink?

   Yes:  Go to  2

   No:  System is normal.

   NOTE: Malfunction indicator light blinks at a cycle of 3 Hz when delivery (test) mode fuse is attached.
2. CHECK HARNESS BETWEEN ECM AND DELIVERY (TEST) MODE FUSE. 
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from ECM.
   3. Measure the resistance between ECM connector and chassis ground.

      Connector & terminal 

      (B134) No. 53 - Chassis ground:

   Is the resistance 1 MΩ or more?

   Yes:  Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H6DO)>ENGINE CONTROL MODULE (ECM)

   No:  Repair the short circuit to ground in the harness between the ECM connector and delivery (test) mode fuse.