C 3500 Truck 2WD V8-454 7.4L (1990)
Vehicle Speed Sensor Signal Buffer: Description and Operation
The Vehicle Speed Sensor (VSS) Buffer is a solid-state device that is used to change the signal from the speed sensor to a digital signal. The VSS
buffer will change the signal from the speed sensor to a signal containing 4000 pulses per mile for the instrument cluster.
The VSS buffer is matched to the final drive and tire size of each vehicle. It must be replaced with the proper buffer to match the final drive and
tire size of that vehicle.
CAUTION: If the final drive or tire size is changed for any reason, the buffer must also be changed to continue to produce an accurate
speedometer/odometer reading. The incorrect buffer will also affect the anti-lock brakes, engine control module, and cruise control module.
