P0500

DTC P0500






Circuit Description
Vehicle speed information is provided to the powertrain control module (PCM) by the vehicle speed sensor (VSS). The VSS consists of a magnetic pickup sensor mounted to the transmission case which interfaces with a rotor pressed onto to the transmission output shaft. The VSS produces a frequency signal that is proportional to vehicle speed. The PCM converts the VSS signal to vehicle speed, displayed on the scan tool in miles per hour and kilometers per hour. The PCM also uses the VSS signal to generate the 4,000 pulses per mile vehicle speed signal used by the instrument cluster.

Conditions for Running the DTC
^ Engine speed is more than 1,250 RPM.
^ Engine load and engine speed acceleration indicate that the vehicle is in gear.

Conditions for Setting the DTC
The vehicle speed sensor indicates a speed of less than 5 km/h (3 mph) for more than 20 seconds.

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

Conditions for Clearing the MIL/DTC
^ The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic runs and passes.
^ The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.
^ The PCM clears the DTC from PCM 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.
5. The resistance measurement will not change if either the VSS high signal circuit or the VSS low signal circuit, but not both, is shorted to ground. The vehicle speed detector in the PCM and the VSS are matched in such a way 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 P0500 to set. The lower resistance value given represents the nominal resistance specification of the VSS at -40°C (-40°F). minus the manufacturing tolerance specification of 10 percent. The higher resistance value given represents the nominal resistance specification of the VSS at 150°C (302°F), plus the manufacturing tolerance specification of 10 percent.
8. This step isolates the short between the VSS and the wiring.
10. Do not skip Step 7. The DMM will detect AC voltage if the VSS high signal circuit is shorted to ground.
13. The replacement PCM must be programmed and the crankshaft position system variation procedure must be performed.