P0500

CIRCUIT DESCRIPTION
The Vehicle Speed Sensor (VSS) circuit is of the magnetic induction type. The gear teeth pressed on the outside diameter of the output shaft assembly induces an alternating current in the sensor as the shaft rotates. The signal goes directly to the VCM. This pulsing action takes place about 40 times per revolution of output shaft of transmission and the VCM calculates the vehicle speed based on the time between pulses. This is a type A DTC.

CONDITIONS FOR SETTING THE DTC
The following conditions will set the DTC:

^ No MAP DTCs.
^ Vehicle speed below 1 mph.
^ Throttle angle below 3%.
^ Engine coolant temperature above 60°C.
^ Engine speed between 1400 and 4400 RPM.
^ MAP below 20 kPa.
^ All conditions met for 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
The VCM sets this DTC. The VCM turns on the Malfunction Indicator Lamp (MIL) when this DTC is reported and 1 failure has occurred.

CONDITIONS FOR CLEARING THE MIL/DTC
The VCM turns the MIL off after 3 consecutive driving trips without a fault condition present. A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 40°F from the start-up coolant temperature and the engine coolant temperature exceeds 160°F during that same ignition cycle) or the scan tool clearing feature has been used.

DIAGNOSTIC AIDS
Check proper calibration for the speedometer.

TEST DESCRIPTION
The numbers below refer to the step numbers in the diagnostic table.

2. This step determines if the DTC P0500 is the result of a hard failure or an intermittent condition.
5. This step checks the wiring, the connections, the VCM, and the VSS.