DTC P0502: Vehicle Speed Sensor Circuit - Low Output: Description

Vehicle Speed Sensor (VSS) system is a pulse generator consisting of a speed sensor assembly, located in case extension, and a toothed vehicle speed sensor reluctor wheel, which is pressed onto final drive carrier assembly. As vehicle drives forward, vehicle speed sensor reluctor wheel rotates. This rotation produces a variable AC signal in pick-up coil that is proportional to vehicle speed. PCM uses this signal to calculate vehicle speed, shift timing and gear ratios. DTC sets when PCM detects a low vehicle speed with a high engine speed while in a drive range.