Antilock Braking System (ABS)

R/R Wheel Speed = 0 MPH:

Circuit Diagram:

L/R Wheel Speed = 0 MPH:

RIGHT REAR WHEEL
The rear wheel speed sensors monitor the speed of each wheel by placing a magnetic coupling next to a toothed ring mounted in the hub and bearing assembly. The signal changes with the wheel speed. If the wheel speed signal is less than 50% of the other wheel speeds while the car is moving, the control module will disable all ABS and turn On the antilock telltale.

CODE PARAMETERS
Code 24 sets if:
^ R/R wheel speed is <50% of other wheels.
^ This code may set anytime the vehicle is moving faster than 8 km/h (5 mph) and not in ABS braking.
^ The failure may first appear to be an intermittent short or open failing code 28 initially and later failing completely causing Code 24 to fail.
^ The vehicle should be driven at speeds above 64 km/h (40 mph) to check for reappearance of these failures.

DIAGNOSTIC AIDS
Before proceeding with the trouble tree, make a thorough visual inspection of the wheel speed sensor circuitry. Closely inspect the inline connector(s) since this is the most likely area for opens or shorts.

Connect the Scan tool, spin the wheel by hand, and monitor the wheel speed. Make a comparison with other wheels.

Visually inspect the sensor for damage. When attempting to diagnose an intermittent problem, use the Scan tool (select Malfunction History from Scan tool ABS menu) to review supplemental diagnostic information. The supplemental data can be used to duplicate a problem.

Intermittents or opens suspected to be at the connectors can be detected by using a diagnostic service probe. Voltage can be read on wires without disconnecting any connectors.

Check the tightness of the female terminal grip with a spare male terminal.