Throttle Position (TP) Sensor
The Throttle Position (TP) sensor is a potentiometer which provides a signal to the PCM that is directly proportional to the throttle plate position. The TP sensor is mounted on the side of the throttle body and is connected to the throttle plate shaft. The TP sensor monitors throttle plate movement and position, and transmits an appropriate electrical signal to the PCM. These signals are used by the PCM to adjust the air/fuel mixture, spark timing and EGR operation according to engine load at idle, part throttle, or full throttle. The TPS is not adjustable.
A faulty throttle position sensor or switch due to loose connections, bad grounds, high resistance in the circuit, or opens in the circuit can cause the following symptoms.
Stalling on Acceleration
Disconnect the negative battery cable.
Disengage the wiring harness connector from the TP sensor.
Using a Digital Volt-Ohmmeter (DVOM) set on ohmmeter function, probe the terminals which correspond to the brown/white and gray/white connector wires on the TP sensor. Do not measure the wiring harness connector terminals, but rather the terminals on the sensor itself.
Slowly rotate the throttle shaft and monitor the ohmmeter for a continuous, steady change in resistance. Any sudden jumps or irregularities in resistance (such as jumping back and forth) indicates a malfunctioning sensor.
Reconnect the negative battery cable.
Turn the DVOM to the voltmeter setting.
Ensuring that the DVOM is set to the voltmeter function is vitally important, because if you measure circuit resistance (ohmmeter function) with the battery cable connected, your DVOM will be destroyed.
Detach the wiring harness connector from the PCM (located behind the lower right-hand kick panel in the passenger compartment), then install a break-out box between the wiring harness connector and the PCM connector.
Turn the ignition switch ON and using the DVOM set to its voltmeter function, measure the voltage between terminals 89 and 90 of the breakout box. The specification is 0.9 volts.
If the voltage is outside the standard value or if it does not change smoothly, inspect the circuit wiring and/or replace the TP sensor.