GM Service Manual Online
For 1990-2009 cars only

    Object Number: 1245793  Size: SH
  1. Remove the connector of vehicle speed sensor, connect 12 volt power supply and voltmeter to the terminal. Do not mistake polarity.

  2. Object Number: 1245792  Size: SH
  3. Rotate the driven gear.
  4. Observe the voltage.
  5. Important: The voltage value will change from approximately 0 to 12 to 0 volts per pulse (1). There will be 4 pulses per revolution (2).

  6. If the result of the inspection is bad, replace the vehicle speed sensor.