Electronic Throttle Control

Most vehicles are equipped with Electronic Power Control (E-gas). In vehicles equipped with E-gas control there is no mechanical connection between accelerator pedal and throttle valve. Position of accelerator pedal is sent to ECM through sensors located in accelerator pedal. Accelerator pedal position is a main input into ECM.

Throttle operation is controlled by the Throttle Valve Control Module (TVCM) located on intake manifold. When engine is running TVCM opens throttle precisely in accordance to position of accelerator pedal. When engine is running ECM can open throttle independently of accelerator pedal.

When engine is started ECM switches EPC indicator in instrument panel on. After ECM checks all components related to E-gas function, EPC indicator is switched off. If E-gas malfunction is recognized, ECM keeps EPC indicator illuminated and stores a DTC in memory. E-gas malfunctions should be repaired as quickly as possible.

To test electronic throttle control, see appropriate DTC under DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.