LEMON Manuals: Even more car manuals for everyone
Home >> Subaru >> 2021 >> Crosstrek Hybrid >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 22 (Engine Control System (2.0L (Except For HEV)) (Diagnostics) (1 Of 4)) >> Diagnostic Procedure With Diagnostic Trouble Code (DTC) >> DTC P0123: Throttle/Pedal Position Sensor/Switch "A" Circuit High >> Notes

DTC P0123: Throttle/Pedal Position Sensor/Switch "A" Circuit High: Notes

WARNING: This page is about a different variant/trim than selected.
  1. - 

    DTC detecting condition: 

    Immediately at fault recognition

    Trouble symptom: 

    • Improper idling
    • Engine stall
    • Poor driving performance

    Wiring diagram: 

    Engine Electrical System Ref. to WIRING SYSTEM (IMPREZA MODEL)>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .

    • IMPREZA MODEL
    G13608090Courtesy of SUBARU OF AMERICA, INC.
    • CROSSTREK MODEL
    G13608091Courtesy of SUBARU OF AMERICA, INC.
    CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR HEV))>GENERAL DESCRIPTION>PREPARATION TOOL>HOW TO USE CHECK BOARD .
    NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR HEV))>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .
  1. CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL (OPEN)  .
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Disconnect the connectors from electronic throttle control.
    4. Measure the resistance of harness between ECM connector and electronic throttle control connector.

      Connector and terminal 

      (E158) No. 29 - (E57) No. 6:

      (E158) No. 30 - (E57) No. 3:

      Is the resistance less than 1 Ω?

      Yes:  Go to  2.

      No:  Repair the open circuit of harness between ECM connector and electronic throttle control connector.

  2. CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL (OPEN)  .
    1. Connect the connector to ECM.
    2. Measure the resistance between electronic throttle control connector and engine ground.

      Connector and terminal 

      (E57) No. 3 - Engine ground:

      Is the resistance less than 5 Ω?

      Yes:  Go to  3.

      No:  Repair the harness and connector.

      NOTE: In this case, repair the following item:
      • Open circuit of harness between ECM connector and engine ground
      • Poor contact of ECM connector
      • Poor contact of coupling connector
  3. CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL (SHORT TO POWER SUPPLY)  .
    1. Turn the ignition switch to ON.
    2. Measure the voltage between electronic throttle control connector and engine ground.

      Connector and terminal 

      (E57) No. 6 (+) - Engine ground (-):

      Is the voltage 5 V or more?

      Yes:  Repair the short circuit to power in the harness between ECM connector and electronic throttle control connector.

      No:  Go to  4.

  4. CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL CONNECTOR  .
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector from ECM.
    3. Measure the resistance between ECM connectors.

      Connector and terminal 

      (E158) No. 27 - (E158) No. 29:

      Is the resistance 1 MΩ or more?

      Yes:  Repair the poor contact of electronic throttle control connector. Replace the electronic throttle control if defective. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO (EXCEPT FOR HEV))>THROTTLE BODY .

      No:  Repair the short circuit to power in the harness between ECM connector and electronic throttle control connector.

scientia non olet · About LEMON Manuals