P0500

DTC P0500





Circuit Description
Vehicle speed information is provided to the engine control module (ECM) by the vehicle speed sensor (VSS). The VSS is a permanent magnet generator that is mounted on the transaxle and produces a pulsing voltage when vehicle speed is over 5 km/h (3 mph). The AC voltage amplitude and frequency increases with vehicle speed. The ECM converts the pulsing voltage into km/h (mph). The ECM supplies the necessary signal to the instrument panel for speedometer, odometer operation and to the cruise control module.

Conditions for Running the DTC
^ No manifold absolute pressure (MAP) sensor DTCs P0107 or P0108.
^ Engine speed is greater than 1,500 RPM.
^ The MAP sensor is greater than 75 kPa.

Conditions for Setting the DTC
Vehicle speed is less than 5 km/h (3 mph) twice during the same ignition cycle for 6.2 seconds.

Action Taken When the DTC Sets
^ The ECM illuminates the malfunction indicator lamp (MIL) on the first consecutive drive trip that the diagnostic runs and fails.
^ The ECM disables Cruise Control.
^ The ECM commands the coolant fan ON.
^ The ECM records the operating conditions at the time when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
^ The ECM stores P0500 in ECM history.

Conditions for Clearing the MIL/DTC
^ The ECM turns OFF the MIL during the third consecutive trip in which the diagnostic runs and passes.
^ The ECM cancels the DTC default actions when the fault no longer exists and the DTC passes.
^ The ECM clears the DTC from ECM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
^ A scan tool can clear the MIL/DTC.

Diagnostic Aids
Ensure the VSS is correctly torqued to the transmission housing.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
4. The vehicle speed detector in the ECM and the VSS are matched so that an open or a short to ground in the VSS low signal circuit will not usually cause a loss of speed signal or a DTC P0502 to set.
7. This step isolates the short between the VSS and the wiring.
9. The DMM will detect AC voltage if the VSS high signal circuit is shorted to ground.