Monitor Description

The ECM uses the throttle position sensor to monitor the throttle valve opening angle.

This sensor includes 2 signals: VTA1 and VTA2. VTA1 is used to detect the throttle opening angle and VTA2 is used to detect malfunctions in VTA1. There are several checks that the ECM performs to confirm proper operation of the throttle position sensor and VTA1.

There is a specific voltage difference expected between VTA1 and VTA2 for each throttle opening angle. If the output voltage difference of the VTA1 and VTA2 deviates from the normal operating range, the ECM interprets this as a malfunction of the throttle position sensor. The ECM will illuminate the MIL and set a DTC. This monitor runs for 2 seconds (the first 2 seconds of engine idle) after the engine is started (1 trip detection logic).