The Throttle Position (TP) sensor is a variable resistor type sensor. The sensor is mounted on the left-hand side of the throttle body, and detects the angle which the throttle valve has been opened. The sensor then relays this information to the Powertrain Control Module (PCM) which, after analyzing the data, regulates the air/fuel mixture.
See Figures 1, 2, 3, 4, 5, 6 and 7
- Backprobe the TP terminal at the TP sensor connector, with the positive lead of a Digital Volt Ohmmeter (DVOM).
- Backprobe the SIG RTN terminal with the negative lead.
- Have an assistant turn the ignition key ON , then depress the accelerator pedal (or manually rotate the throttle lever) so that the throttle lever attains 1 / 4 open, 1 / 2 open, 3 / 4 open and wide-open positions.
- Observe the voltmeter at each of these positions and note the voltage displayed. Compare your readings with the figures in the accompanying charts.
- If the TP sensor readings match the values in the chart, the sensor is working properly. If, however, the TP sensor readings are not as specified, continue with the test procedure.
- Turn the ignition switch OFF .
- Unplug the TP sensor electrical connector, then attach the positive lead of the DVOM to the VREF terminal of the wiring harness connector.
- Turn the ignition switch ON and observe the voltage reading on the DVOM; it should be between 4.5 and 5.5 volts DC.
- If the VREF voltage is within specifications, and the TP voltage readings do not agree with the values displayed in the chart, replace the TP sensor.
REMOVAL & INSTALLATION
See Figures 8, 9 and 10
- Disconnect the negative battery cable.
- If installing the old sensor again, matchmark its location in relation to the throttle body assembly.
- Unplug the Throttle Position (TP) sensor electrical connection.
- Loosen the TP sensor retaining screws and remove the sensor.
- Install the TP sensor and its retaining screws. Tighten the screws to 14.2-20.3 inch lbs. (1.6-2.3 Nm).
- Engage the sensors electrical connection.
- Connect the negative battery cable.
- Unplug the Throttle Position (TP) sensors electrical connection.
- Connect a high impedance Digital Volt Ohmmeter (DVOM) between terminals A and B of the TP sensor.
- Turn the throttle lever to the Wide Open Throttle (WOT) position and check the resistance. The reading should be about 5 ohms.
- Turn the throttle lever to the fully closed position and check the resistance. The reading should be below 1 ohm.
If the readings do not meet the specifications, perform the following adjustment:
- Loosen, but do not remove, the TP sensor retaining screws.
- With the throttle lever in the fully closed position, turn the sensor until the resistance reading on the DVOM is below 1 ohm.
- Turn the throttle lever to the Wide Open Throttle (WOT) position; the resistance reading on the DVOM should be about 5 ohms.
- If the specification cannot be achieved, the throttle body must be replaced.
- Tighten the TP sensor retainers to specification and engage the electrical connections.