Every driver in the UK knows the importance of the MOT. It isn’t just a formality; it is a legal requirement designed to make sure your vehicle is safe, roadworthy, and compliant with environmental standards. Still, many motorists are caught out by simple problems that could have been fixed with a quick check beforehand.
So what will fail an MOT? The truth is, common MOT failures range from worn tyres to dashboard warning lights. In fact, statistics from the Driver and Vehicle Standards Agency (DVSA) show that nearly a third of vehicles fail their first MOT attempt every year, often due to avoidable issues.
Let’s break down the most common MOT failures, why they happen, and how you can avoid them.
Contents
What will fail an MOT immediately?
Certain issues will automatically fail the test. For example:
- A faulty brake light or a missing seat belt.
- Warning lights such as the engine management light, ABS warning light, or airbag warning light are staying on.
- Dangerous tyre condition below the minimum tread depth of 1.6mm.
- Severe faults with the exhaust system leading to a failed emissions test MOT.
- A cracked windscreen that obstructs the driver’s view.
In short, anything that compromises safety or emissions compliance means the vehicle will fail.
Lighting and Signal Problems
Lights and signals are among the most common reasons cars fail the MOT test. Even a single blown bulb can result in an instant failure. MOT testers check:
- Headlights for brightness and alignment.
- Brake lights for correct operation.
- Indicators and hazard lights.
- Number plate lights.
If your daytime running lights fail the MOT because they’re not working properly, that alone could be enough to fail. The good news? A quick check before heading to the test centre can prevent this. Switch on all lights, including the red light on the dashboard, and replace faulty bulbs.
Are Brake Pads Checked In Mot?
Yes. Braking performance is one of the most critical checks. Worn brake pads, leaking fluid, or uneven braking force can all cause MOT failure.
- Thin or unevenly worn pads reduce stopping power.
- A soft pedal may indicate low oil levels in the brake fluid.
- Pulling to one side often suggests issues with the discs or callipers.
If your brakes are not working properly, the car won’t pass its MOT.
Suspension and Steering Issues
Another category of MOT test avoidable failures involves suspension. Testers check:
- Shock absorbers for leaks or poor damping.
- Suspension bushes for wear or cracks.
- The steering wheel for play or stiffness.
If your car makes knocking noises, feels unstable over bumps, or shows excessive body roll, it might fail the test.
Tyres and Tread Depth
Tyre tread depth below 1.6mm is one of the most common MOT failures. Testers also check for:
- Cuts or bulges in the sidewalls.
- Uneven wear from misalignment.
- Tyres not suitable for the vehicle.
You don’t need to wait until the MOT is due. Regular car maintenance checks at home can make sure your tyres are safe.
Exhaust and Emissions
A failed emissions test or MOT is another frequent issue. Common reasons include:
- Faulty catalytic converters.
- Blocked or leaking exhaust system.
- Excessive smoke from diesel vehicles.
Driving your car at higher speeds before the test can help clear deposits in the system. Regular servicing reduces the chance of failure.
Windscreen, Wipers and Washers
A cracked windscreen in the driver’s view is a major fault and will fail the MOT test. Testers also check:
- That the wipers are in working order.
- Washers spray correctly with enough fluid.
If your wipers leave streaks or don’t clear the glass, replace them before booking your MOT.
Seatbelts and Safety Systems
Every seat belt must latch securely, retract smoothly, and show no signs of fraying. If they don’t, the vehicle will fail. This also extends to advanced safety systems. Many drivers ask:
- Will the airbag light fail the MOT? Yes. If the airbag warning light is illuminated, it’s a failure.
- Is ABS light MOT fail? Yes. An ABS warning light that stays on is an MOT failure.
- Does an engine management light fail an MOT? Yes. If the light remains on, the car will fail.
These fall under the new MOT rules warning lights. Testers check all dashboard lights meaning safety system faults.
Registration Plates and VIN
Dirty or damaged registration plates can make your vehicle fail the MOT test. They must be clean, correctly spaced, and firmly attached. The VIN must also be visible for identification.
A quick wash before the MOT is often all that’s needed here.
Dashboard and Warning Lights
Many automotive warning signs appear on dashboards. Examples include:
- Check engine light.
- ABS warning light.
- Airbag light.
- Other car warning lights meaning critical system faults.
If any stay illuminated, they’re considered major faults and will cause the car to fail the MOT test.
Does An Airbag Light Fail Mot?
Yes. Whether you ask “does airbag light fail MOT” or “is airbag light on an MOT failure” — the answer is always YES. Any illuminated airbag system fault counts as a major fault, meaning the vehicle cannot pass its MOT until repaired.
Other Checks That Cause MOT Failure
MOT testers also look at:
- Doors, boot, and bonnet security.
- Fluid leaks.
- Dashboard lights mean serious issues.
- Daytime running lights MOT failure conditions.
Even something as simple as an incorrectly closing bonnet latch can make your vehicle fail.
How to Improve Your Chance of Passing
Here’s the thing. Most MOT issues are avoidable with regular car maintenance. To increase your chance of passing:
- Check all lights and signals weekly.
- Monitor oil levels and top up if needed.
- Inspect tyre tread depth with a 20p coin test.
- Use a free MOT checker online to see when your annual MOT is due. You can often simply enter your vehicle registration to get details.
- Pay attention to automotive warning signs. Don’t ignore them.
By doing these, your car is more likely to pass its MOT first time.
Professional MOT Preparation Services with Paradigm Wills
So, what fails an MOT test most often? Lighting faults, worn tyres, braking issues, warning lights, and exhaust problems top the list. Many of these are quick to spot and fix at home before heading to the test centre.
At Premier Logistics, we understand how important it is to keep your fleet compliant and running. We offer professional MOT preparation services so your business vehicles don’t face unnecessary downtime. Our experts check for common MOT failures and resolve them before the MOT is due.
Call us today on 01530 277 890 or email [email protected].
We provide palletised distribution, contract logistics, warehousing, and transportation services across the UK. Think of us as your one-stop solution for every logistics need.
Reach out via our contact form today and let us take care of the rest.
