P1127 Subaru ECTS Actuator Power Source Circuit Malfunction

Possible causes

– Faulty Electronic Throttle Control System (ETCS) Actuator
– Electronic Throttle Control System (ETCS) Actuator harness is open or shorted
– Electronic Throttle Control System (ETCS) Actuator circuit poor electrical connection

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P1127 Subaru Description

Battery positive voltage is supplied to terminal +BM of the Engine Control Module (ECM) even once when the ignition switch is OFF for the electric Electronic Throttle Control System (ETCS) control system.

If the P1127 Subaru code is stored, the ECM shuts down the power for the ETCS motor and the magnetic clutch, and the ETCS valve is fully closed by the return spring.

However, the opening angle of the ETCS valve can be controlled by the accelerator pedal through the ETCS cable.