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Diagnostic Procedure with Cancel Code: 12

Detected when the brake pedal is depressed, or the error related to the stop light & brake switch occurred.

Trouble symptom: 

Wiring diagram: 

Cruise control system Ref. to WIRING SYSTEM>Cruise Control System>WIRING DIAGRAM

  1. CHECK STOP LIGHT & BRAKE SWITCH  .

    Check the stop light & brake switch. Ref. to CRUISE CONTROL SYSTEM>Stop Light & Brake Switch

    Are the check results for the stop light & brake switch unit, and installation position OK?

    Yes: Go to  2

    No: Replace the stop light & brake switch. Or adjust the installation position.

  2. CHECK STOP LIGHT & BRAKE SWITCH CIRCUIT  .
    1. Turn the ignition switch to OFF.
    2. Disconnect the stop light & brake switch harness connector.
    3. Turn the ignition switch to ON.
    4. Measure the voltage between harness connector terminal and chassis ground.

      Connector & terminal 

      (B65) No. 1 (+) - Chassis ground (-):

    Is the voltage 10 V or more?

    Yes: Go to  3

    No:

    • Check the fuse No. 8 (fuse & relay box).
    • Check for open or short circuit in harness between the stop light & brake switch and the fuse & relay box.
  3. CHECK STOP LIGHT & BRAKE SWITCH CIRCUIT  .

    Measure the voltage between harness connector terminal and chassis ground.

    Connector & terminal 

    (B65) No. 3 (+) - Chassis ground (-):

    Is the voltage 10 V or more?

    Yes: Go to  4

    No:

    • Check the fuse No. 4 (fuse & relay box).
    • Check for open or short circuit in harness between the stop light & brake switch and the fuse & relay box.
  4. CHECK STOP LIGHT & BRAKE SWITCH CIRCUIT  .
    1. Turn the ignition switch to OFF.
    2. Disconnect the harness connector of ECM.
    3. Measure the resistance between ECM harness connector terminal and stop light & brake switch harness connector terminal.

      Connector & terminal 

      Engine type: FA

      (B134) No. 43 - (B65) No. 4:

      (E158) No. 8 - (B65) No. 2:

      Engine type: EJ

      (B136) No. 3 - (B65) No. 2:

      (B136) No. 15 - (B65) No. 4:

    Is the resistance less than 10 Ω?

    Yes: Replace the ECM.

    Ref. to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>Engine Control Module (ECM) . Ref. to FUEL INJECTION (FUEL SYSTEMS) (STI)>Engine Control Module (ECM)

    No: Repair the harness.

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