In most cases you can still drive a car with a faulty ABS sensor, but the anti-lock braking system (ABS) may be disabled and braking safety features like traction control could be affected. Drive cautiously and organize a repair as soon as possible.
What ABS sensors do and why they fail
Wheel speed sensors monitor how fast each wheel is turning and feed data to the ABS controller. This helps prevent wheel lock during braking and supports stability control systems. They can fail due to wiring damage, corrosion, moisture ingress, a damaged reluctor (tone) ring, or a faulty sensor itself. When a sensor fails, the ABS light typically comes on and the system may revert to non-ABS braking behavior.
What happens when an ABS sensor fails?
A faulty ABS sensor usually triggers a warning light on the dashboard and may cause the ABS to disengage. In that case, you’ll still be able to brake, but the wheels can lock up more easily in hard braking, particularly on wet or slick surfaces. Stability/traction control features that rely on wheel speed data may also be reduced or disabled. The exact behavior can vary by vehicle make and model.
Symptoms of a faulty ABS sensor
Common signs that the wheel speed sensor or related ABS components may be failing include several warning signals and braking changes. Look for the following indicators:
- ABS warning light or traction control light illuminated on the dashboard
- Intermittent or persistent loss of ABS function during braking
- Unusual braking feel or longer stopping distances in wet conditions
- Wheel speed sensor fault codes detected on an OBD-II scan
- Visible damage to wiring, connectors, or the wheel hub area
These signs should prompt a professional diagnosis, as continuing to drive could increase the risk of loss of braking control.
Is it legal to drive with a faulty ABS sensor?
Legal requirements vary by country and region, but most places require a vehicle to be maintained in a safe condition. A faulty ABS sensor can cause safety inspections to fail and may affect insurance coverage in the event of an accident. In practice, many drivers continue to operate a vehicle with an ABS fault, but it is not advised because braking safety is reduced and repaired promptly is recommended.
Practical driving steps if you must drive before repair
If you need to drive the vehicle before you can have it repaired, take precautions to minimize risk and accommodate the loss of ABS functionality:
- Drive slowly and increase following distance to give more room for stopping
- Avoid braking hard or abruptly, especially on wet, icy, or loose surfaces
- Use gentle braking and engine braking to reduce the likelihood of wheel lock
- Plan routes that avoid heavy traffic and unnecessary trips until repair is completed
- Have the vehicle inspected and repaired as soon as feasible
These precautions help mitigate risk, but they do not restore full ABS safety. Do not rely on the system in challenging driving conditions.
What to do next: diagnosing and repairing an ABS sensor fault
To properly address an ABS sensor fault, follow a structured diagnostic and repair plan. The steps below are typical for many vehicles, but always consult your service manual or a qualified technician for model-specific procedures.
- Check for stored trouble codes with an OBD-II scanner and note any wheel speed sensor-related codes.
- Inspect fuses and relays related to the ABS system and any stability control modules.
- Visually inspect wheel speed sensor wiring and connectors for damage, corrosion, or loose connections.
- Inspect the wheel speed sensor itself and the reluctor (tone) ring for dirt, contamination, or physical damage.
- Replace or repair faulty components. This may involve replacing the wheel speed sensor, repairing wiring, or replacing a damaged tone ring or wheel hub assembly (some sensors are integrated into the hub).
- After repair, clear codes and test the system in a safe environment to verify ABS and stability control are functioning.
- If sensor replacement is required, ensure proper seating and alignment and recalibrate as specified by the manufacturer.
Professional diagnosis is recommended if you are not experienced with braking systems. Driving with a known ABS fault is not ideal, and a professional repair ensures the system is restored to full capability.
Summary
A faulty ABS sensor can disable ABS and affect stability control, but you can typically still drive in the short term with extra caution. The safer course is to limit driving, especially in adverse conditions, and have the sensor diagnosed and repaired promptly. Expect a diagnosis may involve checking codes, inspecting wiring and the sensor itself, and potentially replacing the sensor or related components. Once repaired, confirm that ABS and stability systems are functioning correctly to restore full braking safety.
How long can I drive with a faulty ABS sensor?
If the ABS warning light is on but there are no other braking symptoms, it's usually safe to drive directly to a repair centre. However, avoid unnecessary journeys and don't drive long distances with an unresolved fault.
How to test if an ABS sensor is faulty?
If this is not the case push in the sensor. Until it touches the exciter ring and perform this test. Again if this still does not fix the problem then you may need to check the wheel bearings.
What happens if you drive with a bad ABS sensor?
Without a functional ABS sensor, your ABS control module won't receive any data about your vehicle's wheel speed. This will force your entire anti-lock braking system to shut down, leaving your wheels at risk of locking.
Is it expensive to fix an ABS problem?
The average cost for ABS module replacement is $1174 to $1301. Enter your vehicle's information to see how much ABS module replacement costs in your local area.