DTC P1581: Starter Disable Relay Stuck On: Notes

DTC detecting condition: 

Immediately at fault recognition

Trouble symptom: 

Auto Start Stop does not operate.

Wiring diagram: 

Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM .

• Model without push button start

  Courtesy of SUBARU OF AMERICA, INC.

  Courtesy of SUBARU OF AMERICA, INC.

• Model with push button start

  Courtesy of SUBARU OF AMERICA, INC.

  Courtesy of SUBARU OF AMERICA, INC.

1. CHECK DTC  .
   1. Turn the ignition switch to ON.
   2. Using the Subaru Select Monitor or a general scan tool, read the DTC of [Engine]. Ref. to COMMON (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC P081A displayed? (Current code)

   Yes:  Check for DTC P081A. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P081A STARTER DISABLE CIRCUIT LOW .

   No:  Go to  2.

2. CHECK STARTER CUT RELAY (STARTER CUT RELAY ON STUCK CHECK)  .
   1. Turn the ignition switch to OFF.
   2. Remove the starter cut relay.
   3. Measure the resistance between starter cut relay terminals.

      Connector & terminal 

      No. 1 - No. 3:

   Is the resistance less than 1 Ω?

   Yes:  Replace the starter cut relay. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>STARTER RELAY .

   No:  Go to  3.

3. CHECK HARNESS BETWEEN ECM CONNECTOR AND STARTER RELAY/STARTER CUT RELAY (SHORT TO POWER SUPPLY)  .
   1. Turn the ignition switch to ON.
   2. Measure the voltage between ECM connector and engine ground.

      Connector & terminal 

      (B62) No. 45 (+) - Engine ground (-):

   Is the voltage 12 V or more?

   Yes:  Repair the short circuit to power supply in harness between the ECM connector and the starter relay or starter cut relay.

   No:  Check for poor contact of ECM connector. Replace the ECM if no fault is found. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) .