2013 Subaru TribecaFACTORY OEM SERVICE PROCEDURE

Diagnostic Procedure

DIAGNOSTIC PROCEDURE

Step Check Yes No
1 CHECK INPUT VOLTAGE OF ECM. 
  1. Turn the ignition switch to ON.
  2. Measure the voltage between ECM and chassis ground.

    Connector & terminal 

    (B136) No. 1 (+) - Chassis ground (-): 

    (B137) No. 7 (+) - Chassis ground (-): 

 Is the voltage 10 - 13 V? Go to step 2  . Repair the open or ground short circuit of power supply circuit.
2 CHECK INPUT VOLTAGE OF ECM. 
  1. Start the engine.
  2. Measure the voltage between ECM and chassis ground.

    Connector & terminal 

    (B136) No. 1 (+) - Chassis ground (-): 

    (B137) No. 7 (+) - Chassis ground (-): 

 Is the voltage 13 - 15 V? Go to step 3  . Repair the open or ground short circuit of power supply circuit.
3 CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL. 
  1. Turn the ignition switch to OFF.
  2. Disconnect the connectors from ECM and electronic throttle control.
  3. Measure the resistance of harness between ECM and electronic throttle control connector.

    Connector & terminal 

    (B134) No. 19 - (E57) No. 5: 

    (B134) No. 29 - (E57) No. 3: 

 Is the resistance less than 1 Ω? Go to step 4  . Repair the harness and connector.
NOTE: In this case, repair the following item:
  • Open circuit in harness between ECM and electronic throttle control connector
  • Poor contact of coupling connector
4 CHECK ECM GROUND HARNESS. 
  1. Connect all connectors.
  2. Turn the ignition switch to ON.
  3. Measure the voltage between ECM and chassis ground.

    Connector & terminal 

    (B134) No. 3 (+) - Chassis ground (-): 

    (B134) No. 4 (+) - Chassis ground (-): 

    (B134) No. 6 (+) - Chassis ground (-): 

    (B137) No. 1 (+) - Chassis ground (-): 

    (B137) No. 3 (+) - Chassis ground (-): 

    (B137) No. 5 (+) - Chassis ground (-): 

 Is the voltage less than 1 V? Repair the poor contact of ECM connector. Repair the harness and connector.
NOTE: In this case, repair the following item:
  • Open circuit in ground circuit Loose engine ground terminal
  • Poor contact of coupling connector
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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