At one point in time, an inoperative speedometer meant one thing: you needed to replace your speedo cable. There were no other ill side effects. Cruise control – if you were lucky enough to have it – would still work because it was vacuum controlled. Your transmission would shift just fine, and you would just guess your speed until you had time to fix it. That, however, was long before we computerized our vehicles – long before engineers started giving them seemingly more intelligence than some of the other drivers on the road. Your 1996 Suburban may not be as advanced as some of the vehicles on the road today, but it has a computer, and numerous sensors that the computer relies on. If you’re experiencing an inoperative speedometer, cruise control failure, or even poor shift quality, your VSS has probably failed. Rest assured it is easy to find and replace, so let's get to it.
Place a floor jack under the center of the radiator core support and lift the front end. Place a jack stand under each frame rail, then lower the front end onto the jack stands.
Locate the vehicle speed sensor. If your Suburban is two-wheel drive it is located on the transmission tail housing, just in front of where the tail housing attaches to the transmission case. If your Suburban is four-wheel drive, the VSS is located on the transfer case, near the output shaft.
Lift up on the locking tab and disconnect the wiring harness from the sensor. Remove the sensor’s retaining bolt, using a socket and ratchet. Remove the sensor from the transmission or transfer case with a slight twisting motion.
Coat the O-ring on a new sensor with fresh transmission fluid, slide the sensor into the transmission or transfer case. Tighten the retaining bolt to 120 inch-pounds with an inch-pound torque-wrench. Connect the wiring harness to the sensor. Lower the truck to the ground.
