DSD Information System
Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control System (2GR-FKS) - Diagnostic Codes (2 Of 6) >> SFI System >> DTC P0120-1C: Throttle / Pedal Position Sensor / Switch "A" Circuit Voltage Out of Range [12/2019 - 10/2022] >> Monitor Description

Monitor Description

The ECM uses the throttle position sensor to monitor the throttle valve opening angle. There are several checks that the ECM performs to confirm the proper operation of the throttle position sensor.

This sensor transmits two signals: VTA1 and VTA2. VTA1 is used to detect the throttle opening angle and VTA2 is used to detect malfunctions in VTA1. The ECM performs several checks to confirm the proper operation of the throttle position sensor and VTA1.

For each throttle opening angle, a specific voltage difference is expected between the outputs of VTA1 and VTA2. If the output voltage difference between the two signals deviates from the normal operating range, the ECM interprets this as a malfunction of the throttle position sensor, illuminates the MIL and stores a DTC.