GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0500: Vehicle Speed Sensor (VSS) Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

VSS Low Signal

--

P0500

--

--

VSS High Signal

P0500

P0500

P0500

--

Circuit/System Description

The vehicle speed information is provided to the powertrain control module (PCM) by the vehicle speed sensor (VSS). The VSS is a permanent magnet generator that is mounted to the transmission and produces a pulsing voltage. The AC voltage amplitude and frequency increases with vehicle speed. The PCM converts the pulsing voltage into km/h (mph). The PCM supplies the VSS signal to the following components:

    • The instrument panel for speedometer and odometer operation
    • The cruise control module

Conditions for Running the DTC

All conditions are met for 2 seconds.

    • DTC P0016, P0106, P0107, P0108, P0120 or P0220 are not set.
    • The engine coolant temperature is 35°C (95°F) or greater.
    • The throttle position (TP) sensor is greater than 3.5 percent.
    • The engine speed is greater than 1,000 RPM.
    • Manifold absolute pressure (MAP) is 40-100 kPa (6-15 psi) with A/C OFF.
    • MAP is 45-100 kPa (7-15 psi) with A/C ON.

Conditions for Setting the DTC

The PCM detects no vehicle speed for 50 seconds.

Action Taken When the DTC Sets

P0500 is a Type B DTC.

Conditions for Clearing the DTC

P0500 is a Type B DTC.

Reference Information

Schematic Reference

Manual Transmission Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Transmission System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References

Special Tools

J 35616 GM-Approved Terminal Test Kit

Circuit/System Verification

  1. Monitor VSS parameter on the scan tool. The VSS parameter should increase as the drive wheel speed increases.
  2. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

Circuit/System Testing

  1. Disconnect the PCM harness connector X1.
  2. Measure for 1,680-3,160 ohms between the VSS high signal circuit terminal 21 and the VSS low signal circuit terminal 20.
  3. If the value is greater than 3,160 ohms test the VSS high signal circuit and the VSS low signal circuit for an open/high resistance. If the circuits/connections test normal, replace the vehicle speed sensor.
    If the value is less than 1,680 ohms test the VSS high signal and the VSS low signal circuits for a shorted together condition. If the circuits/connections test normal, replace the vehicle speed sensor.
  4. Measure for more than 10 ohms of resistance between the VSS high signal circuit terminal 21 and ground.
  5. If the value is less than the specified range, repair the short to ground.
  6. Measure for more than 10 ohms of resistance between the VSS low signal circuit terminal 20 and ground.
  7. If the value is less than the specified range, repair the short to ground.
  8. Reconnect the PCM connector. Disconnect the VSS connector.
  9. Ignition ON, test the VSS high signal circuit terminal 1 for a short to voltage.
  10. If all circuits/connections test normal, test or replace the VSS.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

    •  Vehicle Speed Sensor Replacement
    •  Control Module References for PCM replacement, setup and programming