Diagnostic Aids
Ensure speed sensor wiring is correctly routed and retained. This helps prevent false signals due to electrical noise. Ensure a thorough inspection of all wiring is performed.
On front speed sensors only, check toothed wheel for any large grooves, gouges or marks that might interfere tooth's signal at wheel speed sensor. Check for build-up of foreign material in gaps between teeth in toothed wheel. Worn hub/bearing assembly may cause this fault in extreme cases.