Mechanical Overview

The ABS system

Wheel bearings




It is important that there is no play in the wheel bearings. Significant play in the bearing can result in interference in the signal from the wheel sensors to the control module. This may result in diagnostic trouble codes (DTCs) being stored for these sensors.

Pulse wheel
A loose or damaged pulse wheel may cause interference in the signal from the wheels sensors to the control module. Diagnostic trouble codes (DTCs) may be stored for the wheel sensors.

Wheel sensor




A loose or incorrectly installed wheel sensor may cause interference in the signal to the control module. The wheel sensor must be securely installed on the stub axle (with the sensor at the limit position). Otherwise diagnostic trouble codes (DTCs) may be transmitted from the wheel sensor.

Blocked wheel




Diagnostic trouble codes (DTCs) may be stored for the wheel sensor if a wheel does not move or sticks (due to incorrect adjustment, sticking or seized brakes for example) at start or while driving.

Stop (brake) lamp switch




The stop (brake) lamp switch must be correctly adjusted. Diagnostic trouble codes (DTCs) may be stored for the stop (brake) lamp switch if the switch is incorrectly adjusted.