Subaru Legacy BN/BS (2015-2019) Service Manual: Dtc p2127 throttle/pedal position sensor/switch "e" circuit low

Subaru Legacy BN/BS (2015-2019) Service Manual / Engine (diagnostics)(h6do) / Diagnostic procedure with diagnostic trouble code (dtc) / Dtc p2127 throttle/pedal position sensor/switch "e" circuit low

DTC DETECTING CONDITION:

Immediately at fault recognition

TROUBLE SYMPTOM:

• Improper idling

• Poor driving performance

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode Clear Memory Mode > OPERATION, and Inspection Mode Inspection Mode > PROCEDURE.

WIRING DIAGRAM:

• Engine Electrical System ENGINE TYPE EZ (WITHOUT PUSH BUTTON START) Engine Electrical System > WIRING DIAGRAM

• Engine Electrical System ENGINE TYPE EZ (WITH PUSH BUTTON START) Engine Electrical System > WIRING DIAGRAM

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 (B134) No. 28 — Chassis ground: (B134) No. 31 — Chassis ground:	Is the resistance 1 M- or more-	Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P2127 THROTTLE/PEDAL POSITION SENSOR/SWITCH "E" CIRCUIT LOW	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 M- or more-	Replace the accelerator pedal. Accelerator Pedal	Repair the short circuit to ground in harness between ECM connector and accelerator pedal position sensor connector. Replace the ECM if defective. Engine Control Module (ECM)

1. OUTLINE OF DIAGNOSIS

Detect the open or short circuit of accelerator pedal position sensor 2.

Judge as NG if out of specification.

2. COMPONENT DESCRIPTION

(1)	Engine control module (ECM)	(3)	Accelerator pedal position sensor 2 signal	(4)	Accelerator pedal position sensor
(2)	Accelerator pedal position sensor 1 signal

3. EXECUTION CONDITION

Secondary Parameters	Execution condition
Battery voltage	≥ 6 V

4. GENERAL DRIVING CYCLE

Always perform the diagnosis continuously.

5. DIAGNOSTIC METHOD

If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.

Judgment Value

Malfunction Criteria	Threshold Value
Sensor 2 output voltage	< 0.298 V

Time Needed for Diagnosis: 100 ms

Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

Dtc p2128 throttle/pedal position sensor/switch "e" circuit high

DTC DETECTING CONDITION:Immediately at fault recognitionTROUBLE SYMPTOM:• Improper idling• Poor driving performanceCAUTION:After servicing or replacing faulty parts, perform Clear Memory M ...

Dtc p2123 throttle/pedal position sensor/switch "d" circuit high

DTC DETECTING CONDITION:Immediately at fault recognitionTROUBLE SYMPTOM:• Improper idling• Poor driving performanceCAUTION:After servicing or replacing faulty parts, perform Clear Memory M ...

Other materials:

To arm the system using the keyless access function (if equipped)
Close all windows and the moonroof (if equipped) Turn the push-button ignition switch to the "OFF" position. Open the doors and get out of the vehicle. Make sure that the engine hood is locked. Close all doors and the rear gate/trunk lid. 1) Door l ...