Vehicle Speed Sensor: Description and Operation

VEHICLE SPEED SENSOR

The Vehicle Speed Sensor (VSS) is located on the left hand side of the transfer case. It informs the ECM when vehicle speed is above or below 3 mph. This information is used by the ECM to ensure that the Idle Air Control (IAC) Valve is moved to a position to prevent a stall when the vehicle comes to a stop. A DTC will be displayed if the Mass Air Flow (MAF) Sensor signal is greater than 3 Volts at 2000 - 3000 RPM's.