Circuit Description
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The throttle position (TP) sensors 1 and 2 are located within the throttle body assembly. Each sensor has the following circuits:
- 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 the throttle plate movement. The TP sensor 1 signal voltage at closed throttle is near the 5-volt reference circuit and decreases as the throttle plate is opened. The TP sensor 2 signal voltage at closed throttle is near the low reference circuit and increases as the throttle plate is opened. If the PCM detects that the TP sensor 1 signal voltage is less than the predicted range, DTC P0122 sets.