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.
The TPS is a rotary potentiometer sensor that provides a signal to the PCM that is linearly proportional to the throttle plate/shaft position. The sensor housing has a 3-blade electrical connector that may be gold plated. The gold plating increases the corrosion resistance on the terminals and increases the connector durability. The TPS is mounted on the throttle body. As the TPS is rotated by the throttle shaft, 4 operating conditions are determined by the PCM from the TP.
The operating conditions are:
Removal & Installation
- Disconnect the battery ground cable.
Disconnect the Throttle Position Sensor (TPS) the throttle body electrical connector.
CAUTIONFailure to remove the TPS screws in the following manner will result in damage to the screws.
- First loosen the screws 1-2 full turns using a hand tool, and then use a suitable high speed driver to complete the removal.
Remove and discard the 2 screws and the TPS.
CAUTIONDo not reuse the TPS and screws. A new TPS and screws must be installed.
- Position the new TPS and install the 2 new screws. Tighten to 27 inch lbs. (3 Nm).
- Connect the TPS electrical connector.
- 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.
- 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.
TPS Pin Testing
This pinpoint test is intended to diagnose the following: