DTC P2127 Throttle/Pedal Position Sensor/Switch "E" Circuit Low Input

DTC DETECTING CONDITION:

Immediately at fault recognition
GENERAL DESCRIPTION < Ref. to DTC P2127 THROTTLE/PEDAL POSITION SENSOR/SWITCH "E" CIRCUIT LOW INPUT , Diagnostic Trouble Code (DTC) Detecting Criteria. >

TROUBLE SYMPTOM:

Erroneous idling
Poor driving performance

CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode < Ref. to , OPERATION , Clear Memory Mode. > and Inspection Mode < Ref. to , PROCEDURE , Inspection Mode. >.

WIRING DIAGRAM:

Fig 1: Wiring Diagram - Throttle/Pedal Position Sensor Circuit (Low Input)

Courtesy of SUBARU OF AMERICA, INC.

DTC P2127 DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK OUTPUT VOLTAGE OF ACCELERATOR PEDAL POSITION SENSOR. Turn the ignition switch to ON. Measure the voltage between ECM connector terminals. Connector & terminal (B136) No. 28 (+) - (B136) No. 35 (-): Shake the ECM harness and connector, accelerator pedal position sensor.	Is the voltage more than 0.4 V?	Go to step 2 .	Go to step 3 .
2 CHECK POOR CONTACT IN CONNECTORS. Check poor contact in connectors between ECM and accelerator pedal position sensor.	Is there any poor contact in connectors between ECM and accelerator pedal position sensor?	Repair the poor contact in connectors.	Connector has returned to its normal condition at this time. A temporary poor contact in the connector might have been the cause.
3 CHECK HARNESS BETWEEN ECM AND ACCELERATOR PEDAL POSITION SENSOR. Turn the ignition switch to OFF. Disconnect the connector from ECM. Disconnect the connector from accelerator pedal position sensor. Measure the resistance between ECM connector and accelerator pedal position sensor. Connector & terminal (B136) No. 28 - (B315) No. 2: (B136) No. 16 - (B315) No. 1:	Is the resistance less than 1 Ω?	Go to step 4 .	Repair the open harness connector.
4 CHECK HARNESS BETWEEN ECM AND ACCELERATOR PEDAL POSITION SENSOR. Measure the resistance between ECM connector and chassis ground. Connector & terminal (B136) No. 28 - Chassis ground: (B136) No. 16 - Chassis ground:	Is the resistance more than 1 MΩ?	Go to step 5 .	Repair the ground short of harness.
5 CHECK POWER SUPPLY TO 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. 1 (+) - Engine ground (-): Shake the ECM harness and connector, while monitoring value of voltage meter.	Is the voltage 4.5 - 5.5 V?	Go to step 6 .	Repair the poor contact in ECM connector. If problem persists, replace the ECM. < Ref. to ENGINE CONTROL MODULE (ECM) . >
6 CHECK ACCELERATOR PEDAL POSITION SENSOR. Measure the resistance of accelerator pedal position sensor. Terminals No. 1 - No. 6:	Is the resistance 0.75 - 3.15 kΩ?	Go to step 7.	Replace the accelerator pedal position sensor.
7 CHECK ACCELERATOR PEDAL POSITION SENSOR. Measure the resistance of accelerator pedal position sensor when accelerator pedal is released. Terminals No. 2 - No. 6:	Is the resistance 0.15 - 0.63 kΩ?	Go to step 8 .	Replace the accelerator pedal position sensor.
8 CHECK ACCELERATOR PEDAL POSITION SENSOR. Measure the resistance of accelerator pedal position sensor when acceleration pedal is being depressed. Terminals No. 2 - No. 6:	Is the resistance 0.28 - 1.68 kΩ?	Repair the poor contact in ECM connector. If problem persists, replace the ECM. < Ref. to ENGINE CONTROL MODULE (ECM) . >	Replace the accelerator pedal position sensor.