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DTC P0122: Throttle/Pedal Position Sensor/Switch "A" Circuit Low: Notes

DTC detecting condition:

Immediately at fault recognition

Trouble symptom:

Improper idling
Engine stalls.
Poor driving performance

CAUTION: After servicing or replacing faulty parts, perform Clear Memory Mode Ref. to ENGINE (DIAGNOSTICS) (STI)>Clear Memory Mode>OPERATION , and inspection mode Ref. to ENGINE (DIAGNOSTICS) (STI)>Inspection Mode>PROCEDURE .

Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM>Engine Electrical System>WIRING DIAGRAM .

G12456893

Courtesy of SUBARU OF AMERICA, INC.

CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL CONNECTOR .
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 between ECM connector and chassis ground.
  Connector & terminal
  
  (B134) No. 19 - Chassis ground:
  
  (B134) No. 18 - Chassis ground:
  
  (B134) No. 18 - (B136) No. 4:
Is the resistance 1 MΩ or more?

Yes: Go to 2

No: Repair the ground short circuit of harness between ECM connector and electronic throttle control connector.
CHECK SHORT CIRCUIT INSIDE THE ECM .
1. Connect the connector to ECM.
2. Measure the resistance between electronic throttle control connector and engine ground.
  Connector & terminal
  
  (E57) No. 6 - Engine ground:
Is the resistance 1 MΩ or more?

Yes: Replace the electronic throttle control. Ref. to FUEL INJECTION (FUEL SYSTEMS) (STI)>Throttle Body .

No: Repair the ground short circuit of harness between ECM connector and electronic throttle control connector. Replace the ECM if defective. Ref. to FUEL INJECTION (FUEL SYSTEMS) (STI)>Engine Control Module (ECM) .