The vehicle speed sensor in a 2004 Chevrolet Tahoe is located on the top right side of the transmission housing, just above the pan area. This sensor determines the vehicle speed by measuring the rotation of internal transmission components. The vehicle speed sensor, or VSS, sends this speed data to the powertrain control module, or PCM. The PCM uses the data to manage the engine functions and ensure all vehicle systems are operating properly. One example is that the PCM compares the VSS data to the wheel speed sensor data to determine which, if any, wheels are locking up. Replacement vehicle speed sensors are available from most local auto parts stores and licensed General Motors dealerships.
Shift the transmission into park and turn off the engine. Apply the parking brake, open the hood, and disconnect the negative battery terminal using a battery terminal wrench. Place wheel chocks behind the rear wheels.
Raise the vehicle using an automotive jack and support it with jack stands. Check to make sure that the vehicle is resting securely on the jack stands. Crawl underneath the vehicle and locate the VSS.
Disconnect the vehicle speed sensor’s electrical connector. Remove the VSS mounting bolt with a metric socket and a ratchet. Remove the VSS using a twisting and pulling motion. Remove the VSS O-ring seal with your index finger and thumb.
Install the new O-ring seal, which comes with the new VSS, onto the new VSS and coat it with a thin film of automatic transmission fluid.
Install the VSS into the transmission using a twisting and pushing motion.
Tighten the VSS retaining bolt to 97 inch-pounds using a metric socket and an inch-pound torque wrench. Reconnect the vehicle speed sensor’s electrical connector. Exit from underneath the vehicle.
Raise the vehicle using the automotive jack and remove the jack stands, one side at a time, then lower the vehicle back to the ground. Reconnect the negative battery terminal using the battery terminal wrench and close the hood. Test drive the vehicle to ensure it operates properly.
