Circuit Description
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The vehicle speed sensor (VSS) assembly provides vehicle speed information to the powertrain control module (PCM). The VSS assembly is a permanent magnet generator. The VSS produces alternating current (AC) as the rotor teeth on the output shaft of the transmission (2WD) or transfer case (4WD) pass through the sensor's magnetic field. The frequency and amplitude of the AC waveform both increase as vehicle speed increases.
If the PCM detects no vehicle speed for a specified length of time while other sensors indicate that the vehicle is moving, DTC P0500 sets. DTC P0500 is a type B DTC.