Will Car Fail mot with the ABS Light On?
When the ABS (Anti-lock Braking System) light appears on your dashboard, it can be worrying. Many drivers ask the same question: will my car fail mot with abs light ABS light on? In the UK, an illuminated ABS warning light means there is a fault in your car’s braking system. Because ABS is an important safety feature, it can affect whether your car passes or fails an MOT inspection. This guide explains what the ABS system does, what the warning light means, and whether you can still pass an inspection if it is on.
What the ABS System Does
The Anti-lock Braking System (ABS) helps prevent the wheels from locking up when braking suddenly. It improves control and stability, especially on slippery or wet roads.
Without ABS, your tyres can lock during heavy braking, making it harder to steer or stop safely. For this reason, all modern cars registered after 2004 must have a working ABS system.
What the ABS Warning Light Means
When you start your car, the ABS light briefly appears to show the system is checking itself. It should turn off within a few seconds.
If it stays on while driving, the system has detected a problem. Common causes include:
- A faulty ABS wheel speed sensor
- A cracked or dirty ABS tone ring
- Low or contaminated brake fluid
- Faulty ABS pump or control module
- Corroded wiring or loose connectors
Although your main brakes will still work, the ABS feature will be disabled. This means the wheels could lock up during an emergency stop, increasing stopping distances.
Will a Car Pass an MOT or Inspection with the ABS Light On?
The short answer is no, a car will fail the MOT test if the ABS warning light is on.
According to the DVSA (Driver and Vehicle Standards Agency), the ABS light must come on at ignition, then turn off after the system check. If it remains illuminated, it indicates a fault in the braking system, which is an automatic MOT failure.
However, for a pre-purchase inspection such as one from CAREXAMER, the car is not being tested for MOT pass or fail but for its condition. In that case, a glowing ABS light will be listed as a safety concern or advisory fault and should be repaired before driving the car regularly.
Common Causes of an ABS Light Staying On
| Cause | Description | Typical UK Repair Cost |
|---|---|---|
| Faulty ABS Wheel Sensor | Sensor not reading wheel speed correctly | £100 – £250 per sensor |
| Broken ABS Tone Ring | Cracked or corroded tone ring | £80 – £200 |
| Faulty ABS Pump or Module | Main ABS unit failure | £400 – £900 |
| Low or Dirty Brake Fluid | Fluid contamination or leak | £60 – £120 |
| Wiring Damage | Broken or corroded electrical connections | £100 – £250 |
How to Fix the ABS Warning Light
- Check brake fluid levels and top up if low.
- Scan the car for diagnostic fault codes using an OBD2 tool.
- Replace faulty sensors, rings, or wiring based on diagnostics.
- Reset the ABS light after repairs with a professional diagnostic scanner.
Many garages can diagnose and fix ABS problems within a few hours.
Is It Safe to Drive with the ABS Light On?
Driving with the ABS light on is not immediately dangerous, as your main brakes will still work. However, you lose the added safety of anti-lock braking.
In dry conditions, braking distances might only be slightly longer, but in wet or icy conditions, stopping distances can increase dramatically.
If both the ABS and brake warning lights appear together, stop driving immediately and have the car checked. This can indicate a serious brake system failure.
How to Prevent ABS Problems
- Change brake fluid every two years to prevent corrosion.
- Keep wheel sensors clean during brake or tyre work.
- Avoid jet washing near the wheel hubs to prevent damage.
- Repair faults quickly, as ignoring them can cause expensive module failures.
Pre-Purchase and MOT Advice
If you are buying a used vehicle, always ensure the dashboard lights go out after starting the engine.
A CAREXAMER pre-purchase inspection will include checking dashboard warnings, braking performance, and electronic system faults. This can help you avoid buying a car that may fail its MOT soon after purchase.
If your car fails its MOT because of the ABS light, you must have it repaired and retested before legally driving it again.
Conclusion
A car will not pass its MOT inspection if the ABS light is on. The ABS system is a key safety component, and any fault must be fixed before the vehicle can be considered roadworthy.
Typical repair costs range from £100 for a faulty sensor to around £900 for a complete ABS pump replacement, depending on the issue.
Ignoring the ABS light can lead to unsafe braking and an MOT failure. Always diagnose the fault early and consider a CAREXAMER inspection if you want a full professional report before repairs or purchase.
Buying a used VW. Buying used vauxhall, BMW, Jaguar, Ford, Volvo, Range rover, Bentley, Aston Martin, Porsche, Ferrari, Lamborghini, Maserati, Hyundai, Tesla, Honda, Pagani