Wheel Speed Sensor Check
- Perform a comprehensive visual inspection of speed sensor. Ensure damaged wires are not present. Front wheel speed sensor clearance is .012-.035" (.30-.89 mm). Rear wheel speed sensor clearance is .008-.028" (.20-.70 mm). Clearance is measured between end of sensor and sensor rotor.
- Ensure end of speed sensor is not contaminated. Using a DVOM, measure resistance between speed sensor terminals. Front wheel speed sensor resistance should be 800-1200 ohms.
- Rear wheel speed sensor resistance should be 550-800 ohms. If resistance is not within specification, replace speed sensor. Perform a comprehensive visual inspection of sensor rotor. If any damage is noted, replace sensor rotor.
- To check AC output voltage of wheel speed sensors, disconnect ABS computer harness connector. Using Harness Adapter (MB991132), connect male end to vehicle harness. Jack up vehicle and place on jackstands.
- Rotate wheel of wheel speed sensor to be checked one half to one turn a second. Measure voltage between Harness Adapter terminals indicated in WHEEL SPEED SENSOR VOLTAGE table.
WHEEL SPEED SENSOR VOLTAGE
| Application |
Millivolts |
| Front Left |
| Terminals No. 4 & 5 |
50 or more |
| Front Right |
| Terminals No. 21 & 23 |
50 or more |
| Rear Left |
| Terminals No. 7 & 9 |
50 or more |
| Rear Right |
| Terminals No. 24 & 26 |
50 or more |