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Home >> Subaru >> 2015 >> WRX STI >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls (Diagnostics) (H4DOTC) (STI) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC P2127 Throttle/Pedal Position Sensor/Switch "E" Circuit Low Input >> Wiring Diagram
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DTC P2127 Throttle/Pedal Position Sensor/Switch "E" Circuit Low Input: Wiring Diagram

Fig 1: Throttle/Pedal Position Sensor/Switch "E" - Wiring Diagram (Low Input)
G10265893Courtesy of SUBARU OF AMERICA, INC.
DIAGNOSTIC 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 between ECM connector and chassis ground.

    Connector & terminal 

    (B135) No. 22 - Chassis ground: 

    (B135) No. 31 - Chassis ground: 

Is the resistance 1 MΩ or more? Go to step . Repair the short circuit to ground in harness between ECM connector and accelerator pedal position sensor connector.
2 CHECK SHORT CIRCUIT INSIDE THE ECM. 
  1. Connect the connector to ECM.
  2. Measure the resistance between accelerator pedal position sensor connector and chassis ground.

    Connector & terminal 

    (B315) No. 3 - Chassis ground: 

Is the resistance 1 MΩ or more? Replace the accelerator pedal. <Ref. to ACCELERATOR PEDAL .> Repair the short circuit to ground in harness between ECM connector and accelerator pedal position sensor connector. Replace the ECM if defective. <Ref. to ENGINE CONTROL MODULE (ECM) .>