The vehicle speed sensor provides a vehicle speed signal to the ECM. On conventional speedometers, the speed sensor consists of a reed switch which transforms vehicle speed into a pulse signal. The input received from the sensor is used to regulate ignition timing and decell fuel shut off.
See Figure 1
- Remove the speedometer cable and cable pinion housing, from the transaxle.
- Disconnect the 20 pin electrical connector from the ECM.
- Connect an ohmmeter between connector terminal 10 and a known good ground.
- Turn the ignition switch to the ON position.
- Observe the ohmmeter while rotating the speedometer drive gear. The reading should fluctuate between continuity and open, twice per revolution.
- If the sensor did not perform as specified, inspect the wiring between the instrument cluster and the ECM. If the wiring is okay, replace the VSS.
REMOVAL & INSTALLATION
The instrument panel mounted VSS is integral part of the vehicle speed sensor. Refer to Chassis Electrical for speedometer head Removal and Installation information.