GM S-Series Pick-ups and SUV's 1994-1999 Repair Guide

Wheel Speed Sensor



1994 EBCM and 1994-96 VCM Equipped Vehicles

For wheel speed sensor testing on these models, refer to and follow the appropriate flow chart(s) for the ABS system used on your vehicle in this section.

1997-97 4WAL Equipped Vehicles

See Figure 1

Some speed sensor intermittent malfunctions may be difficult to locate. Care should be taken not to disturb any electrical connections prior to an indicated step in the following procedure. This will ensure that an intermittent connection will not be corrected before the source of the malfunction is found.

  1. Make sure the ignition is OFF .
  3. Raise the vehicle and support it with jackstands.
  5. Using a 5% salt water solution (two tablespoons of salt and 12 ounces of water), thoroughly spray the wheel speed sensor.
  7. Unplug the five-way EBCM harness connector.
  9. Using a Digital Volt Ohmmeter (DVOM) set to read resistance, probe terminals C and E of the five-way EBCM harness connector.
  11. Compare your readings to the accompanying temperature versus resistant chart shown.
  13. If the resistance was within specification, inspect the harness connector for signs of damage and/or corrosion. Perform all necessary repairs, clear all DTC's and repeat the test.
  15. If the resistance was not within specification, unplug the sensor harness from the sensor.
  17. Using a fused jumper wire, jumper terminals A and B of the two-way EBCM-to-Wheel Speed Sensor (WSS) harness connector.
  19. Using the DVOM, measure the resistance between terminals C and E of the five-way EBCM harness connector.
  21. If the resistance reading is not less than two Ohms. Repair an open or high resistance in wires coming from the speed sensor (these wires are usually dark green and tan).
  23. If the resistance is less than two Ohms, measure the resistance between terminal A and terminal B of the sensor connector and compare your readings with the temperature versus resistance chart shown.
  25. If the resistance is not within specification, replace the sensor.
  27. If the resistance is within specification, check all connectors and harnesses for damage and repair as necessary.

Click image to see an enlarged view

Fig. Fig. 1: Wheel speed sensor temperature versus resistance chart-1997-99 4WAL ABS systems