Possible causes

– Faulty Accelerator Pedal Position Sensor
– Accelerator Pedal Position Sensor harness is open or shorted
– Accelerator Pedal Position Sensor circuit poor electrical connection

When is the code detected?

The Powertrain Control Module (PCM) detects that the difference between Accelerator Pedal Position (APP) sensor 1 and APP sensor 2 is more than the predicted value.

Symptoms

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

P1125 CADILLAC Description

The accelerator pedal position (APP) sensor 1 and the APP sensor 2 are potentiometer type sensors, each with the following circuits:
? A 5-volt reference circuit
? A low reference circuit
? A signal circuit
The control module provides the APP sensors with a 5-volt reference circuit and a low reference circuit. The APP sensors then provide the control module signal voltages proportional to pedal movement. The APP sensor 1 signal voltage is low at rest and increases as the pedal is depressed.
The APP sensor 2 signal voltage is low at rest and increases as the pedal is depressed. When the control module detects that the APP sensor 1 and the APP sensor 2 signal circuits are out of correlation with each other, DTC P1125 sets.

CADILLAC Technical Service Bulletins for P1125 code