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Home >> Subaru >> 2018 >> WRX STI >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics) (2 Of 4) (STI) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC P0512: Starter (Switch) Request Circuit >> Notes
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DTC P0512: Starter (Switch) Request Circuit: Notes

DTC detecting condition: 

Immediately at fault recognition

Trouble symptom: 

Failure of engine to start

CAUTION: After servicing or replacing faulty parts, perform Clear Memory Mode Ref. to ENGINE (DIAGNOSTICS) (STI)>Clear Memory Mode>OPERATION , and inspection mode Ref. to ENGINE (DIAGNOSTICS) (STI)>Inspection Mode>PROCEDURE .

Wiring diagram: 

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

G11574201Courtesy of SUBARU OF AMERICA, INC.
  1. CHECK PUSH BUTTON IGNITION SWITCH  .

    Operate the push button ignition switch.

    Does it operate smoothly without catch?

    Yes:  Go to  2

    No:  Replace the push button ignition switch. Ref. to SECURITY AND LOCKS>Push Button Ignition Switch .

  2. CHECK DTC  .
    1. Clear the memory using the Subaru Select Monitor. Ref. to ENGINE (DIAGNOSTICS) (STI)>Clear Memory Mode .
    2. Start and idle the engine for three minutes or more.

    Is DTC P0512 displayed? (Current malfunction)

    Yes:  Go to  3

    No:  Even if DTC is detected, 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.
  3. CHECK HARNESS BETWEEN ECM AND KEYLESS ACCESS CM  .
    1. Turn the ignition to OFF.
    2. Disconnect the connector from ECM.
    3. Turn the ignition to ON.
    4. Measure the voltage between ECM connector and chassis ground.

      Connector & terminal 

      (B136) No. 16 (+) - Chassis ground (-):

    Is the voltage 10 V or more?

    Yes:  Repair the short circuit to power supply in harness between ECM connector and keyless access CM connector.

    No:  Repair the poor contact of ECM connector.