Theory Of Operation

WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

Due to the integration of the Powertrain and Transmission Control Modules the New Generation Control Module III will be referred to as the Powertrain Control Module (PCM). The 3-wire TPS (4.7L V-8 Engine) provides the PCM with an input signal voltage that represents the throttle blade position of the throttle body. The Throttle Position Sensor (TPS) is connected to the throttle blade shaft. As the position of the throttle blade changes, the output voltage of the TPS changes.

The PCM supplies approximately 5.0 volts to the TPS. The TPS output voltage (input signal to the PCM) represents the throttle blade position. The PCM receives an input signal voltage from the TPS. This will vary in an approximate range from 0.26 volts at minimum throttle opening (idle), to 4.49 volts at maximum opening (wide open throttle).

The Accelerator Pedal Position Sensor (APPS) is currently used only with the 5.7L V-8 engine. The APPS is a linear potentiometer. It provides the PCM with a voltage signal proportional to the angle, or position of the accelerator pedal. The APPS signal along with inputs from other sensors is used by the PCM to calculate the throttle plate position.

A mechanical cable is used between the accelerator pedal and the APPS assembly. Although a cable is used between the accelerator pedal and the APPS assembly, a mechanical cable is not used between the accelerator pedal and the throttle body. The throttle plate position is electronically controlled by the PCM.