| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. |
Circuit Description
VSS detects rotation speed of transmission output shaft and sends signals to ECM. The ECM determines vehicle speed based on these signals.
DTC is set if there is no VSS signal to ECM while vehicle is being driven or if park/neutral position switch is off. Possible causes are
- Vehicle speed sensor.
- Open or shorted VSS circuit.
- ECM.