Contents: Removal ↧ Installation ↧
The throttle position (TP) sensor is a potentiometer connected to the throttle shaft on the throttle body. The TP sensor circuit consists of a 5-volt supply circuit and a ground circuit, both of which are controlled by the engine control module (ECM). The ECM calculates the throttle position by monitoring the voltage on this signal circuit. As the accelerator pedal is moved, the TP sensor output voltage changes, changing the throttle angle. When the throttle is closed, the TP sensor output is low, about 0.5 V. As the throttle is opened, the output increases so that when the throttle is wide open, the output voltage will be 5 V.
The ECM calculates fuel delivery based on the throttle valve opening angle (determined by the driver). A non-functioning or worn throttle position sensor can cause a one-time fuel splash from the injector and unstable idling, as the ECM senses that the throttle is currently changing its position. A malfunction in any of the throttle position sensor circuits should cause a fault code (DTC) of P0121 or P0122 to be assigned. If one of the fault codes is assigned, the ECM will replace the default value of the throttle position sensor, and to some extent the vehicle's performance will be compensated.
Trouble code P0121 is the cause of high idle speed.
Removal
1. Disconnect the "-" battery cable.
2. Remove the throttle position sensor connector.
3. Remove the throttle position sensor mounting bolts and throttle body.
Installation
1. With the throttle valve closed, install the TP sensor onto the throttle shaft. Align the TP sensor with the bolt holes.
2. Tighten the throttle position sensor mounting screws to 2 Nm.
3. Connect the TP sensor connector.
4. Connect the "-" wire of the battery.
