P0500

DTC P0500

Circuit Description
A toothed wheel mounted on the output shaft of the transmission generates an AC voltage pulse as it moves past the vehicle speed sensor (VSS). The VSS contains a permanent magnet surrounded by a coil of wire, which produces a magnetic field. The toothed wheel interrupts the magnetic field that generates an AC voltage pulse. As the vehicle speed increases the AC voltage pulse rate also increases.

Conditions for Running the DTC
^ DTCs P0107, P0108, P0117, P0118, P0121, P0122 or P0123 are not set.
^ The engine coolant temperature (ECT) is more than 35°C (95°F).
^ No idle control system DTCs P0506 or P0507 are not set.
^ The engine speed is more than 1,000 RPM.
^ The throttle position (TP) sensor angle is 5-100 percent.
^ The manifold absolute pressure (MAP) is between 40 - 100 kPa (6 - 15 psi) when the A/C is OFF.
^ The MAP is between 45 - 100 kPa (7 - 15 psi) when the A/C is ON.
^ All conditions are met for 2 seconds.

Conditions for Setting the DTC
The powertrain control module (PCM) detects vehicle speed at 0 km/h (0 mph) for 100 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 records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC
^ The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL and the 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. 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. Refer to the latest Techline procedures for PCM reprogramming.

Step 1 - Step 6:

Step 7 - Step 14: