Q: What is the location and function of the Throttle Position Sensor (TPS)?
A: The Throttle Position Sensor (TPS) on 2004 and earlier engines is attached to the firewall side of the throttle body. Problems with the TPS or motor can cause intermittent bursts of fuel from the injectors and an unstable idle because the PCM thinks the throttle is moving. The PCM is constantly comparing the driver's input from the accelerator pedal position sensor to the actual throttle position at the throttle body. A problem with the TPS circuits will set a diagnostic trouble code. To replace a defective TPS, disconnect the cable from the negative terminal of the battery. Disconnect the electrical connector at the TPS and remove the two mounting screws. Installation is the reverse of removal. On 2005 and later engines, the throttle body is operated by an electric throttle control motor instead of a cable. On these models, the TPS is part of the throttle motor assembly and cannot be replaced separately. If there are problems with the throttle control motor or the TPS, the complete throttle body must be replaced.