Pickup 1997

Wheel Speed Sensors

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Removal & Installation



The speed of the rear wheels is monitored by a sensor located in the rear differential housing. A toothed wheel or rotor rotates with the drive line, passing in front of the sensor. As the teeth of the ring pass the sensor, the peaks and valleys generate a small AC voltage which is transmitted to the R-ABS module. The module compares the signals and reacts to rapid loss of wheel speed at a particular wheel by engaging the R-ABS system.

The sensor may be removed for testing or replacement, but the companion flange on the differential must be removed for access. Removing the flange also allows access to the toothed rotor.

  1. Before servicing the vehicle, refer to the Precautions Section.
    NOTE
    If working near and/or around the SRS system and components, be sure to disable the SRS system. After disabling the system wait three minutes or more before servicing the vehicle. Disconnect the air bag module connector.



    Click image to see an enlarged view

    Fig. Air bag module connector location

  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Raise and safely support the rear of the vehicle.
  6.  
  7. Matchmark and remove the rear driveshaft from the rear differential.
  8.  
  9. Detach the sensor harness at the connector.
  10.  
  11. Remove the nut holding the companion flange to the differential.
    NOTE
    This nut should be tight and may be difficult to remove.

  12.  
  13. Remove the companion flange with the rotor from the differential housing.
  14.  
  15. Remove the retaining bolts holding the speed sensor, then remove the sensor.

    Click image to see an enlarged view

    Fig. ABS rear speed sensor and related components



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    Fig. ABS hydraulic circuit



    Click image to see an enlarged view

    Fig. ABS rear speed sensor harness connectors



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    Fig. ABS rear speed sensor and related components

  16.  

To install:


NOTE
Be sure to use new fasteners, as required.

  1. Installation is the reverse of the removal procedure.
  2.  
  3. Fit the sensor into place and install the bolts. Tighten the bolts to specification.
  4.  
  5. Place the companion flange in position and start the retaining nut. Tighten the nut to 175 ft. lbs. (236 Nm).
  6.  
  7. Attach the sensor connector to the wire harness.
  8.  
  9. Install the driveshaft.
  10.  
  11. Using the CONSULT-III diagnostic tool, or equivalent, perform the SRS self diagnostic test and any reconnect/relearn procedures, as required.
  12.  

 
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