Vehicle Speed Sensor: Description and Operation

VEHICLE SPEED SENSOR DESCRIPTION

The VSS is an electronic relay that is mounted on the transaxle. As the transaxle turns the VSS, the VSS provides the speedometer with a vehicle speed input (voltage pulses). This input is used to drive the speedometer. The speedometer then converts the Vehicle speed input into a more precise waveform and provides the Powertrain Control Module (PCM) and the cruise control module with its own vehicle speed input. The cruise control module converts this input into a vehicle speed. For vehicle speed sensor replacement procedures, refer to Vehicle Speed Sensor (VSS) Replacement in Automatic Transmission - MU4, Vehicle Speed Sensor (VSS) Replacement in Manual Transmission - MK5, or Vehicle Speed Sensor (VSS) Replacement in Manual Transmission - MTN.

The RES/ACC switch can also be used to tap-up vehicle speed. In order to do this, the cruise control system must be engaged and operating. Tapping-up is performed by quickly moving the cruise control switch up into the RES/ACC position and releasing it (or tapping the switch into the RES/ACC position). Do not hold the cruise control switch in the RES/ACC position, or the cruise control system will enter the accelerate mode. Tap-up is a function in which cruise speed can be increased by 1.6 km/h (1 mph) increments (one tap = 1.6 km/h [1 mph] increase).