The Throttle Position Sensor (TPS) signal represents the throttle blade position. As the position of the throttle blade changes, the resistance of the TPS changes. The Powertrain Control Module (PCM) supplies approximately 5 volts to the TPS. The TPS output voltage (input signal to the PCM) represents the throttle blade position. The TPS output voltage to the PCM varies from approximately 0.6 volt at minimum throttle opening (idle), to a maximum of 4.5 volts at Wide Open Throttle (WOT).
Along with inputs from other sensors, the PCM uses the TPS input to determine the current engine operating conditions. The PCM also adjusts the fuel injector pulse width and the ignition timing based on these inputs.
Removal & Installation
- Before servicing the vehicle, refer to the Precautions Section.
- Remove the negative battery cable.
- Remove the throttle body.
- Remove the Throttle Position Sensor (TPS) mounting screws.
- Remove the TPS.
- The throttle shaft end of the throttle body slides into a socket in the TPS. The socket has two tabs inside it. The throttle shaft rests against the tabs. When indexed correctly, the TPS can rotate clockwise a few degrees to line up the mounting screw holes with the screw holes in the throttle body. The TPS has slight tension when rotated into position. If it is difficult to rotate the TPS into position, install the sensor with the throttle shaft on the other side of the tabs in the socket.
- Tighten the TPS mounting screws to 44 inch lbs. (5 Nm) torque.
- After installing the TPS, the throttle plate should be closed. If the throttle plate is open, install the sensor on the other side of the tabs in the socket.
- Install the throttle body.
- Connect the negative battery cable.
- Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Throttle Body and the Powertrain Control Module (PCM).
- Look for any chafed, pierced, pinched, or partially broken wires.
- Look for broken, bent, pushed out or corroded terminals.
- Inspect the Throttle Body for any condition that would result in an incorrect signal, such as damage or contamination.
- Inspect and clean all PCM, engine, and chassis grounds that are related to the most current DTC.
- If numerous trouble codes were set, use a wire schematic and look for any common ground or supply circuits.
- For any Relay DTC-s, actuate the Relay with the scan tool and wiggle the related wire harness to try to interrupt the actuation.
- Use the scan tool to perform a System Test if one applies to failing component. A co-pilot, data recorder, and/or lab scope should be used to help diagnose intermittent conditions.