Vehicle Speed Sensor (VSS)

DESCRIPTION
- The Vehicle Speed Sensor (VSS) is a magnetic pickup that sends the Powertrain Control Module (PCM) vehicle speed information.
- The VSS sensor is mounted externally on the left-side of the transmission extension housing.
- The PCM uses VSS information to help determine Electronic Pressure Control (EPC), shift scheduling and Torque Converter Clutch (TCC) operation.

SYMPTOMS
- Electronic Pressure Control (EPC shorted to ground or failed low may result in a false VSS DTC. Diagnose EPC concerns first, then recheck VSS.
- High EPC pressure, resulting in harsh engagements and/or firm/harsh shifts.
- Incorrect shift schedules, unexpected downshifts may occur at closed throttle.
- No TCC engagement.

DIAGNOSTIC TROUBLE CODES:
P0500, P0501, P0503, P1500, P1501