The Throttle Position Sensor (TPS) and throttle actuating DC motor are integral to the throttle body. The throttle body is a non-serviceable item; replace the throttle body as an assembly.
The throttle blade will not close completely when engine is shut down. This engine off blade position is for start up. The electric throttle body will adjust the throttle blade for idle control as the idle air control valve adjusted idle speed previously on cable actuated throttle bodies. The electric throttle body will also adjust the throttle blade for normal driving operation. The throttle blade will move to the engine off blade position if throttle body codes are set to provide air for limp-in mode.
Removal & Installation
The throttle position sensor attaches to the side of the throttle body.
- Before servicing the vehicle, refer to the Precautions Section.
- Remove the air cleaner lid and makeup air hose. Loosen the clamp and relocate the assembly.
Remove the negative battery cable.
- Disconnect the electrical connector from the Throttle Position Sensor (TPS) (2).
- Remove the TPS mounting screws.
Remove the TPS.
The throttle position sensor attaches to the side of the throttle body (1).
The throttle shaft end of the throttle body slides into a socket in the TPS (2). Note to make sure that the rubber O-ring is in place and seated around the TPS rotor housing surface. The socket has 2 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, reinstall the sensor with the throttle shaft on the other side of the tabs in the socket of the TPS. Tighten the mounting screws to 53 inch lbs. (6 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.
- Attach the electrical connectors to the TPS.
- Install the negative battery cable.
- Install the air cleaner lid and makeup air hose and tighten the clamp.
- 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.