Circuit Description

Accelerator Pedal Position (APP) sensor is located on throttle body and has 2 variable resistors integral to APP sensor. APP sensor monitors accelerator position and is connected with accelerator pedal by accelerator wire. APP sensor signal voltage (0-5 volts) to ECM changes in proportion to accelerator pedal opening angle. ECM controls throttle motor based on APP sensor voltage signals. If DTC P1120 is present, ECM turns off power to throttle motor and magnetic clutch and throttle valve is fully closed by the return spring. When this occurs, opening angle of throttle valve is controlled by accelerator pedal by means of a throttle cable. DTC is set when ECM detects voltage is out of range on VPA or VPA2 circuits. Possible causes are:

• APP sensor circuit is open or shorted.
• Defective APP sensor.
• Defective ECM.