P0500

DTC P0500

Test 1-5:

Test 6-12:

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.
^ Throttle position is open.
^ Engine vacuum is less than 22.89 kPa (3.320 psi).

Conditions for Setting the DTC
Vehicle speed is less than 5 km/h (3 mph) 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 refer to the step numbers on the diagnostic table.
1. This step ensures that the technician performed a Diagnostic System Check - Manual Transmission.
2. This step tests to see if the ECM is receiving a signal from the VSS using the scan tool.
3. This step tests the entire VSS system for proper output voltage.
4. This step tests the VSS High Signal and VSS Low Signal circuits for opens, shorts and high resistance.
5. This step ensures the technician inspects the VSS related mechanical components and mounting.
6. This step verifies if the ECM has taken required action after setting DTC P0500.
7. This step tests the VSS High Signal and VSS Low Signal circuits for total circuit resistance. 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.
11. This step replaces the ECM. The replacement ECM must be programmed and the crankshaft position system variation procedure must be performed.
12. This step validates that the repair has fixed the DTC under normal operating conditions.