Monitor Description

M/T: 

The throttle position sensor varies its resistance with the angle of the throttle valve. The ECM applies a regulated reference voltage to the throttle position sensor (+) terminal and calculates the angle of the throttle valve based on the current voltage at the throttle position sensor signal terminal.

When the throttle valve is near the fully closed position, the output voltage of the throttle position sensor is low. When it is near the fully open position, the output voltage is high.

The ECM checks the indicated angle of the throttle valve during "stop and go" conditions. If the indicated angle (or voltage) in the closed throttle position is out of the specified range 8 times or more, the ECM interprets this as a malfunction in the throttle position sensor and sets a DTC.

SMT: 

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

This sensor including two signals, VTA and VTA2. VTA is used to detect the throttle opening angle and VTA2 is used to detect malfunction in VTA. There are several checks that the ECM performs confirm proper operation of the throttle position sensor and VTA.

There is a specific voltage difference expected between VTA and VTA2 for each throttle opening angle. If the voltage output difference of the VTA 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.