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

DTC DETECTING CONDITION:

Immediately at fault recognition
GENERAL DESCRIPTION < Refer to DTC P2123 THROTTLE/PEDAL POSITION SENSOR/ SWITCH "D" CIRCUIT HIGH INPUT , Diagnostic Trouble Code (DTC) Detecting Criteria. >

TROUBLE SYMPTOM:

Erroneous idling
Poor driving performance

WIRING DIAGRAM:

Fig 1: Accelerator Position Sensor - Wiring Diagram

G05031791

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC CHART

Step	Check	Yes	No
1 CHECK ACCELERATOR PEDAL POSITION SENSOR OUTPUT. Turn the ignition switch to ON. Read the data of main accelerator pedal position sensor signal using Subaru Select Monitor. NOTE: Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". < Refer to SUBARU SELECT MONITOR . >	Is the voltage less than 4.8 V?	Go to step 2.	Go to step 3.
2 CHECK POOR CONTACT. Check poor contact of connector between ECM and accelerator pedal position sensor.	Is there poor contact?	Repair the poor contact.	Temporary poor contact occurred, but it is normal at present.
3 CHECK HARNESS BETWEEN ECM AND ACCELERATOR PEDAL POSITION SENSOR. Turn the ignition switch to OFF. Disconnect the connectors from ECM. Disconnect the connectors from accelerator pedal position sensor. Measure the resistance between ECM connector and accelerator pedal position sensor connector. Connector & terminal (B135) No. 29 - (B315) No. 5:	Is the resistance less than 1 Ω?	Go to step 4.	Repair the open circuit of harness connector.
4 CHECK HARNESS BETWEEN ECM AND ACCELERATOR PEDAL POSITION SENSOR. Connect the ECM connector. Measure the resistance between accelerator pedal position sensor connector and engine ground. Connector & terminal (B315) No. 5 - Engine ground:	Is the resistance less than 5 Ω?	Go to step 5.	Repair poor contact in ECM connector. Replace the ECM if defective. < Refer to ENGINE CONTROL MODULE (ECM) . >
5 CHECK HARNESS BETWEEN ECM AND ACCELERATOR PEDAL POSITION SENSOR. Connect the ECM connector. Turn the ignition switch to ON. Measure the voltage between accelerator pedal position sensor connector and engine ground. Connector & terminal (B315) No. 6 (+) - Engine ground (-):	Is the voltage less than 6 V?	Go to step 6.	Repair the battery short circuit of harness between ECM connector and accelerator pedal position sensor connector.
6 CHECK HARNESS BETWEEN ECM AND ACCELERATOR PEDAL POSITION SENSOR. Turn the ignition switch to OFF. Disconnect the connectors from ECM. Measure the resistance between ECM connectors. Connector & terminal (B135) No. 23 - (B135) No. 21: (B135) No. 23 - (B135) No. 22:	Is the resistance more than 1 MΩ?	Repair the poor contact of accelerator pedal position sensor connector. Replace the accelerator pedal position sensor if defective.	Repair the short circuit to sensor power supply.