DTC P1120: Throttle Position Sensor 1 Circuit: Description

The Throttle Position (TP) sensors 1 and 2 are located within the throttle body assembly. Each sensor has the following components:

• A 5-volt reference circuit.
• A low reference circuit.
• A signal circuit.

This provides the Powertrain Control Module (PCM) with a signal voltage proportional to throttle plate movement. TP sensor 1 signal voltage at closed throttle is about 5-volt reference and decreases as the throttle plate is opened. TP sensor 2 signal voltage at closed throttle is about the low reference and increases as the throttle plate is opened. When TP sensor 1 signal voltage is not within the predicted range, this DTC sets.