Symptoms
- Pulsing or grabbing sensation from the brake pedal on dry roads
- Possible rhythmic noise from a wheel matching the pulsing
- ABS or related warning light may be lit
Likely causes
- CommonFaulty or dirty wheel speed sensorSends incorrect speed data that the ABS module misreads as slipping.
- CommonDamaged tone ring on the wheel hubPhysical damage or debris on this ring throws off sensor readings.
- PossibleLoose or corroded sensor wiring connectorIntermittent connection issues can cause sporadic false activation.
- Less commonUneven tire sizes or significantly different tread wear side to sideCan occasionally confuse the system into thinking one wheel is slipping.
What to do
- Check that all four tires are the same size and have reasonably similar tread wear.
- Note which wheel seems to be involved, if you can tell from sound or feel.
- Check for the ABS or related warning light being on, which usually goes along with this.
- Have the code read at a shop to identify the specific wheel sensor at fault.
- Have that sensor and the tone ring inspected and cleaned or replaced as needed.
- Have connectors checked for corrosion, especially in wet or salted-road climates.
Tools and parts
Wheel speed sensorSearch: “ABS wheel speed sensor for your car make and model”
When to call a pro
See a mechanic to diagnose the specific sensor causing false ABS activation on dry roads.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.