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HOMESERVICE MANUALSSUBARU2014FORESTER 2.5I, ENG CD FB25BA, STANDARD TRANSREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT VARIANT/TRIMSECTION 9 (ENGINE CONTROL SYSTEM (DIAGNOSTICS) (H4DOTC))DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)DTC P2123: THROTTLE/PEDAL POSITION SENSOR/SWITCH "D" CIRCUIT HIGH INPUTWIRING DIAGRAM
2014 Subaru Forester 2.5i, Eng CD FB25BA, Standard Trans

DTC P2123: Throttle/Pedal Position Sensor/Switch "D" Circuit High Input: Wiring Diagram

2014 Subaru Forester 2.5i, Eng CD FB25BA, Standard TransSECTION Wiring Diagram
WARNING: This page is about a different variant/trim than selected.
  • Engine electrical system turbo engine model (without push button start) < Ref. to TURBO MODEL (WITHOUT PUSH BUTTON START) , WIRING DIAGRAM, Engine Electrical System. >
  • Engine electrical system turbo engine model (with push button start) < Ref. to TURBO MODEL (WITH PUSH BUTTON START) , WIRING DIAGRAM, Engine Electrical System. >
    Fig 1: Throttle/Pedal Position Sensor/Switch Wiring Diagram
    G09480986Courtesy of SUBARU OF AMERICA, INC.
DTC PROCEDURE

Step Check Yes No
1 CHECK HARNESS BETWEEN ECM AND ACCELERATOR PEDAL POSITION SENSOR CONNECTOR. 
  1. Turn the ignition switch to OFF.
  2. Disconnect the connectors from ECM and accelerator pedal position sensor.
  3. Measure the resistance of harness between ECM and accelerator pedal position sensor connector.

    Connector & terminal 

    (B134) No. 17 - (B315) No. 6: 

    (B134) No. 31 - (B315) No. 5: 

 Is the resistance less than 1 Ω? Go to step 2  . Repair the open circuit in harness between ECM and accelerator pedal position sensor connector.
2 CHECK HARNESS BETWEEN ECM AND ACCELERATOR PEDAL POSITION SENSOR CONNECTOR. 
  1. Connect the connector to ECM.
  2. Measure the resistance between accelerator pedal position sensor connector and chassis ground.

    Connector & terminal 

    (B315) No. 5 - Chassis ground: 

 Is the resistance less than 5 Ω? Go to step 3  . Repair the harness and connector.
NOTE: In this case, repair the following item:
  • Open circuit of harness between ECM and engine ground
  • Poor contact of ECM connector
  • Poor contact of coupling connector
3 CHECK HARNESS BETWEEN ECM AND ACCELERATOR PEDAL POSITION SENSOR CONNECTOR. 
  1. Turn the ignition switch to ON.
  2. Measure the voltage between accelerator pedal position sensor connector and chassis ground.

    Connector & terminal 

    (B315) No. 6 (+) - Chassis ground (-): 

 Is the voltage 5 V or more? Repair the short circuit to power supply in the harness between the ECM and accelerator pedal position sensor connector. Go to step 4  .
4 CHECK HARNESS BETWEEN ECM AND ACCELERATOR PEDAL POSITION SENSOR CONNECTOR. 
  1. Turn the ignition switch to OFF.
  2. Disconnect the connector from ECM.
  3. Measure the resistance between ECM connectors.

    Connector & terminal 

    (B134) No. 17 - (B134) No. 30: 

 Is the resistance 1 MΩ or more? Repair the poor contact of accelerator pedal position sensor connector. Replace the accelerator pedal if defective. < Ref. to ACCELERATOR PEDAL . > Repair the short circuit to power supply in the harness between the ECM and accelerator pedal position sensor connector.
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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.
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  • • 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.