Electronic Engine Power Control

Electronic Engine Power Control

For EPC, the throttle valve is not operated by a cable from the accelerator pedal. There is no mechanical connection between the accelerator pedal and the throttle valve.

The EPC system consists of the Throttle Valve Control Module (throttle body, throttle position sensor and motor in one unit), the ECM and Throttle Position/Accelerator Pedal position sensor. The EPC system contains multiple ECM inputs including traction control, cruise control and transmission shift control that contribute to recognizing, controlling and monitoring the position of the throttle valve by the ECM.

The position of the accelerator pedal is communicated to engine control module (ECM) by the throttle position sensor / accelerator pedal position sensor 2 (variable resistance sensors stored in one housing) that are connected to the accelerator pedal.

Operation of the throttle valve occurs via an electric motor in the throttle valve control module.

With engine off and ignition switched on, the ECM controls the throttle drive according to the throttle position sensor / accelerator pedal position sensor 2. This means, if the accelerator pedal is pressed half way, the throttle motor opens the throttle valve to the same degree; i.e. throttle valve is then opened approximately half way.

When an EPC fault is recognized by the ECM, the EPC lamp in the cluster illuminates and the system will default to limp in mode (limited control).