Possible causes

Harness or connectors (The APP sensor 2 circuit is open or shorted.)

Accelerator pedal position sensor (Accelerator pedal position sensor 2)

When is the code detected?

An excessively high voltage from the APP sensor 2 is sent to ECM.

Symptoms

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

P1228 Description

The accelerator pedal position sensor is installed on the upper end of the accelerator pedal assembly. The sensor detects the accelerator position and sends a signal to the ECM.

Accelerator pedal position sensor has two sensors. These sensors are a kind of potentiometers which transform the accelerator pedal position into output voltage, and emit the voltage signal to the ECM. In addition, these sensors detect the opening and closing speed of the accelerator pedal and feed the voltage signals to the ECM. The ECM judges the current opening angle of the accelerator pedal from these signals and controls the throttle control motor based on these signals.

Idle position of the accelerator pedal is determined by the ECM receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine operation such as fuel cut.

P1228 Information for specific makes

P1228 BUICK
P1228 CADILLAC
P1228 CHEVROLET
P1228 FORD
P1228 GMC