/ Motoring

Warning lights on? Your car will fail its MOT test

New tougher MOT rules will require your car dashboard’s warning lights to be working. If they don’t, your car will fail its MOT test. Is this a much needed safety improvement or a route to more rip offs?

The MOT test now includes a ‘Malfunction Indicator Lamp’ check. This requires the examiner to visually check that warning lights for electronic stability control, safety restraint systems, anti-lock braking systems and tyre pressure monitoring systems are not permanently illuminated.

The requirement came into effect on 1 January to comply with a revised European testing directive. It will be highlighted as an ‘advisory’ item only until 31 March, but from 1 April onwards, vehicles will fail an MOT if these lights are illuminated.

It’s just a visual check – so doesn’t require any diagnostic equipment to evaluate the actual cause of the light being on, but you can bet your bottom dollar the garage will charge you to investigate why a light is on (it will scan the system for a fault code, pointing to the cause).

The risk of rogue warning lights

When I recently asked my Renault dealer to investigate a warning light, the first thing they said was that there would be a £45 charge for a diagnostic check, then additional rectification costs depending on what that revealed.

My ‘fault’ was a service warning to check the handbrake (not covered by the new MOT rules as far as I can tell) which came on after the battery was disconnected.

As an ex-mechanic, I checked the physical components of the handbrake and there wasn’t an actual handbrake fault. In my view, it was simply a rogue indication because of the loss of power to the system. But to find that out for sure, I have to stump up £45, without even thinking of any consequential costs.

Don’t get me wrong, I completely agree that these lights are important – and if functioning correctly, they can let you know of a genuine safety risk.

So it seems sensible to make these an advisory notice. But, to me, the idea that they constitute an automatic MOT failure (without a proper investigation) leaves motorists open to being charged extra, perhaps simply because modern electronic systems are still too quirky and can display rogue signals from time to time. Would your car pass these new MOT rules?


I did rather sourly reflect on the irony that an apparent glitch in the instrument cluster of my VWAG car temporarily rendered it unable to display the status of some warning systems, and this included the ABS warning light. Rather inconveniently, I could not start the car until I interrupted battery power for an hour. Meanwhile, the system was smart enough that the ABS knew it was unable to report it’s Good Status to the instrument cluster, so logged a fault in the ABS that then shows as a latched ABS fault when the instrument cluster got over it’s glitch. So it wasn’t a real fault at all, but the ABS warning light was latched and the car would have failed an MOT. Time and expense later, I located a friendly vagcom guy who sorted out clearing the latched fault, confirming it was the instrument cluster dropping the ball, and not in any way attributable to the condition of the ABS,
Better (more resilient) system design, please.

just had mot on my proton,failed purely for hazard warning switch not flashing when switched on.Spoken to numerous people in the trade and its 50/50 wether this is a requirement as long as lights are flashing and it shows them flashing on the dash,

My car also failed on this a few years ago. The switch replacement was pretty cheap.

I have an amber power steering malfunction light on my dash, but the power steering works fine with no problems. It cost me £2500. and eight weeks without a car to have it fixed, the diagnostics came up with a body error code. A specialist stripped down the steering and wiring, downloaded a new updated E C U and B M U programme from Ford USA, TWICE! fitted various electronic sensors and switches. But the Amber light is still on. The Garage got fed up of looking at it and said to me there in no fault but the light won’t go off!
So a £80000. Car when I bought it, only passed its MOT because it has flumexed the specialist, who passed the MOT for me. The light came on in December 2015 and it is still on now,but the power steering still works without any problems.

Julie mcgrann says:
21 December 2017

Our Vauxhall Meriva dashboard showed 3 different codes. One was a rear light. The garage said they’d changed the bulb and when we drove off the code was still up as faulty. As well as the other two codes. One of which was another light, even though that also was working perfectly.

We had taken the car in because the power steering sounded odd, crunchy, this wasn’t a fault listed on the dashboard fault lights though!
They fixed the power steering pipe at £150 total and said it would need to have a diagnostic evaluation for the warning lights which he couldn’t do.

We had a diagnostic evaluation that cost £35 and left the car to have the “necessary” repairs!
That cost us £195
This garage told us the fault indicator light that showed the airbag light fault would have to be done at a Vauxhall garage!
As we drove off the car still showed the 3 faults on the dashboard! One of which was still the rear light, even though it was working.

This led me to believe there is a malfunction with the fault finding system! Showing rogue signals!

What can be done?

My Toyota auris just failed its mot just because 1 of my indicator lights on dash didn’t light up. Surely that can’t be a fail. All exterior lights working fine.

Regulations are regulations rules are rules laws are laws and MUST be followed or you face the consequences Susan If no one broke laws rules etc. there would have been no need for them to be made

Susan – If one of the malfunction indicator lights does not work when tested (for a short period after you turn on the ignition) it would not warn you of a potentially dangerous problem such as a fault with the braking system.

Graham Ruddock says:
4 June 2018

A £400 light Bulb!!!
My son’s Chevolet Spark would have failed its MOT because the dashboard indicator light to show that his rear fog light was on was not working. I don’t have an issue with the need to have such a working warning light, but the indicator was a failed LED on the binnacle circuit board in an area sealed behind an opaque screen. The only solution was to buy and replace the entire instrument binnacle. The part cost was around £300 plus around another £100 to fit and would have taken around 10 days to import to UK. I suspect such a replacement could cost a great deal more on other makes and models of cars. Without it, no MOT.
Actually, we were lucky to find a SH binnacle from a car breaker for £50 and changed it ourselves. That really was lucky, as there were not going to be many working binnacles lying around for a Chevy Spark.
Clearly, the binnacle was not designed to allow the ready replacement of such warning lights, nor a simple repair. This could represent yet another significant additional cost for all motorists. Whatever teh potential cost, I advise you check your warning lights WELL BEFORE your next MOT.
Oh yes – and disabling the rear fog is not permitted. Providing a separate panel mounted warning light may have been the only other affordable option (NEWS BULLETIN: shares in Halfords rise – too late for Maplin!).

This problem only exists because we have allowed manufacturers to design products that are easy to assemble but very costly to repair. With cars it means and expensive repair whereas with TVs and washing machines the failure of an inexpensive component can result in a product being not economically repairable. We now have cars where the engine has to be lifted to replace the timing belt and some where the front bumper has to be removed to replace a headlight bulb.

Which is why I’d like Which? and others to look at repairability – feasibilty and cost – as part of a product assessment. Common vulnerable components should be simple to replace by the owner. On a car this should include lights and routine service items. The complexity of cars these days – particularly electronic items – are integrated for technical, reliability and cost reasons. The risk of failure is often very low. It maybe we need EC regulations to address the problem.

It’s such a general problem that the only workable solution is to have legislation, in my view. Thinking about Graham’s example, is there any car currently produced where it would be a simple job to replace a LED or other minor part in an instrument cluster. With good design that could be easy. I’m not suggesting that manufacturers deliberately set out to make parts difficult and expensive to replace, and it might just be because products are designed for ease of assembly rather than maintenance.

Such items as LED’s are probably rrgarded as so reliable- certainly as low power indicator lights – that integrating them in an electronic panel is sensible. Probably a good deal more relisble thsn making them replaceable. But routine serviceable items should be easy to get at, like an exterior light bulb that fails – usually when it’s dark 🙂
.EC construction regulations could achieve that. We could apply the same philosophy to domestic appliances.

I’m not referring to the LED but the cost of the assembly and fitting, Malcolm. Graham gave a price of £300 plus an estimated cost of £100 for fitting.

I cannot think of any reasonably modern car where it is a simple matter to remove the instrument panel and I know of a few where it is very difficult. Thanks to poor design, failure of a component worth pence can result in the consumer being charged hundreds of pounds for a repair. I agree that construction regulations are the way forward but it would be far better if manufacturers behaved sensibly in the first place.

Occasionally manufacturers do make our lives easier. The switch assembly for my car lights can be removed and replaced within seconds. Unfortunately replacing the adjacent headlamp levelling control would be a major job.

This comment was removed at the request of the user

I had wondered whether to mention that car electrical systems are not necessarily simple the days and anyone who wants to find out more can look up the ‘CAN bus’ system that is used in cars.

There is a general problem that repairing modern products can be much more difficult and expensive than in the past, and with better design that need not be the case. As you say, it’s probably not as simple as a faulty LED, so perhaps this was not the best example.

The point I was suggesting was that when something is inherently reliable, replaceability is less of an issue. It is expensive to remove and strip a gear box should a bearing fail, for example, but relatively unlikely. Sometimes integrating components can lead to a more reliable and cheaper assembly than if they were individually repaceable. But I do think that wear and tear components and those of limited life should be relatively accessible and easy to replace.

Why not design cars so that the instrument panel and other components are readily accessible by making it easy to remove the dashboard? That should not significantly increase the cost of assembly but would make repairs easier and less expensive. Perhaps the manufacturers should be given a deadline to improve cost effective repairability and if this is not effective then go ahead with legislation.

I’ve made the point about integrated assemblies being cheaper to build and possibly more reliable but this can easily make repairs to cars extremely expensive, as has been mentioned by other contributors to this Convo. Replacing washing machine bearings was once a simple job but thanks to the tank and drum being an integrated assembly in most modern machines it may not be economically viable to effect a repair.

After my MOT I will be booking my car in for a service and replacement of the timing belt. I expect that the latter will be an expensive job, as with my last car. With the previous cars I did the job myself without any problem.

I’ve never had a problem with a gearbox but yesterday a friend told me that he has had a second one fail in his Renault van.

This comment was removed at the request of the user

There is no doubt that car reliability has improved greatly over the years and you no longer need a diesel engine for reliability. In nearly six years and 50k miles I have not had to spend a penny on anything other than servicing. A friend’s Polo with a small petrol engine has done 186k miles and it’s still running fine. I noticed that the engine management light was on but apparently the emissions are unaffected so the car passes the MOT after the garage resets the light.

If you are unlucky, the cost of car repairs can be horrendous.

Graham Ruddock says:
21 June 2018

Can I first of all congratulate the contributors that responded to my comments for the quality of their arguments and thus the value the ensuing debate – some very useful suggestions I feel (if it had been on the BBC’s Have Your Say site, someone would have blamed the whole situation on Brexit!).

Having successfully help my son fit the new S/H Binnacle, I can report that subsequently, the MOT was successfully delivered. Getting the existing dashboard apart was the fun bit. A couple of screws were fairly easy to find and access, but two small screws were behind the steering wheel. Eventually I realised that if you rotated the steering wheel to a particular angle, it was possible to get a screwdriver onto them. That left the screws that were accessed from behind clip-on plastic covers. That is where we all get extremely nervous. Where and how to apply the necessary force, which side of the joint line is to be pushed inwards and how much force to apply. In fact, the garage had broken one cover piece trying to prize it off, but fortunately that was on the part being replaced.

So my contribution to the debate is for there to be a requirement for a few standard ways to indicate how and where to “unclip” clipped together components – even if that upsets the “purity” on some designers concepts (just consider that a challenge to be integrated into the visual design). There is a standard marking for AC and DC power adaptors which we all have learnt, so a simple symbol system like that ought to be possible. As this mostly applies to plastic moulding, they should be simple to incorporate.

Car repair handbooks that show how to do such tasks would be useful. I had a BMC one for my first Mini, and Haines manuals are helpful, but they only cover more popular models. Whether they go into such detail I do not know.

My sons always look on YouTube and forums when they have a car problem that, they tell me, help in both diagnosis and details of the repair operation.

William says:
24 July 2018

I’m afraid the law is an ass! Dashboard warning lights where originally put in for the drivers peace of mind, not for an excuse to right off hundreds of thousands of cars!! They aren’t reliable and are always malfunctioning. Most of the warning lights don’t cause the vehicle to be dangerous and should never be included in the test! As I said, it’s another government scam that mainly affects the poor!

This comment was removed at the request of the user

I would have hoped that most people would want to know if their car had a fault that could affect safety. The problem is simply that warning lights can sometimes illuminate when no fault exists or the fault has been rectified. If there is a design fault with a particular model of car then perhaps owners should be making claims for compensation.

I wonder how common the problem of rogue warning lights is. Like many people I know, I have not had a problem.

Bought a car, on finance. Since, having it. NO, traction control or abs. No, lights, on dashboard. Tracking, was out, resulting. Low speed, kerbing. A puncture, not a scratch, on alloy’s. Dealership, saying it’s cause of kerbing. That lost, everything. Although, never, had warning lights!

This comment was removed at the request of the user

Andy says:
7 March 2019

Okay, just failed my NoT as my ESC traction control warning light is lit up. OBD reader shows no diagnostic codes! So no fault but a warning light!

David Gardner says:
9 March 2019

If a engine management light is on will it fail the mot?
If the light does not come on at all will it fail?

If the ‘engine malfunction indicator lamp’ shows a problem then the car will fail the MOT test: https://www.gov.uk/government/publications/mot-changes-from-may-2018-guidance-for-mot-testers/mot-inspection-manual-changes

The light should come one for a short time after the ignition key is turned on and if it does not, that suggests tampering, which would also be a fail.

If a service light is on with a check injection message, can’t reset, will it fail?

This seems to be a common problem with Renault cars, Colin, though opinion seems to be divided as to what is the cause. As with an engine management light it can warn that the car may be producing excessive emissions and would be an MOT failure. If an engine is not operating correctly you can cause damage that could be expensive to fix.

Stephen says:
11 April 2019

The M.O.T tester tried to fail my car because the offside indicator was not orange enough
when flashing behind lens:
He removed bulb from holder expecting the paint to have peeled off (exposing the clear glass)
but it was like new and he reluctantly agreed that it was correct shade of orange as per manufacture.
Safety first is all well and good; but as a cynic I am forced to ask myself if this is yet another underhanded
way of forcing older cars of the road by failing them on often minor faults such as dash warning lights knowing
that such a fault can sometimes cost 4 figures to correct.
Owners of relatively new diesel cars ( their purchase encouraged by government ) will be the next victims in this on going M.O.T crusade!!
The ULEZ will take out a lot of good vehicles as well- an enforced scrappage scheme – but you get
no pay out!!
I note that the London ”Black cabs ” are being given extra exemption because Mr Khan
knows that they could bring London to a halt with a yellow vest blockades etc so he dare not antagonise them:
Never mind that they are an on going source of daily pollution.
When is the British public going to wake up an realise it’s being ”taken for a ride”??

My car (Skoda Fabia Mk1, diesel, 2003) apparently doesn’t have a dedicated EML lamp. It uses the GLOW-PLUG lamp instead. The garage failed it anyway – when I tried to explain this to the mechanic all I got was ‘my mate has a skoda and his has one!’. Right then. I am also lead to believe that this test point is only required for cars registered from 2008. Can anybody confirm any of these points?

Does a Skoda Fabia Diesel (2003) have an EML? I am told it uses the glow-plug lamp. Also, isn’t the functioning EML test point only for cars on or after 2008?

SkyLark says:
25 August 2019

As your Fabia is pre 1st July 2008 and a Diesel then the EML light is not a testable item. The same is true for petrol cars first used before 1st July 2003 where again the EML light is not part of the test. You might want to go back to the garage and ask them to check the current MoT tester manual. The above info is at the end of section 8.2.1


Note; the MoT manual in the 9th March link above has now been updated to the version above.

When my fuel is low an orange led is displayed. When the ABS sensor failed, not affecting the braking in any way, a similar orange led is displayed. Question, would my car fail for being low on fuel because the led is lit. Also what is the point of sensors if you have no trust in them. These regulations are a money spinning device designed by manufacturers and politicians who will in all essence never own an older car and will never have to worry about finding the finances the majority of the electorate have to struggle with.

This comment was removed at the request of the user

“9. Fuel and engine oil. Your car will need enough of both fuel and engine oil for its MOT. The MOT tester will need to run the engine to check exhaust emission levels and might refuse to test your car if the fuel or engine oil level is too low.

The following system characteristics can be recognised when wheel speed sensors fail:
The ABS warning light illuminates: Fault code is stored :The wheels lock during braking : Incorrect or pseudo regulation interventions; Failure of further systems

So I’d suggest it would be in your own interests to replace a faulty sensor, as well as to pass the MoT.

Hi Robert – I cannot see how the ABS can work if a sensor has failed. An ABS failure will not prevent the brakes working as normal most of the time but you lose the advantages of the system under adverse driving conditions.

Sometimes warning lights do malfunction but if you just ignore them there is no way of knowing when a genuine fault occurs.

Thank you found info re pre 2008 Deisel very helpful re management light thank you skylark.
Re car MOT

niraj says:
7 January 2020

if your engine light is on and your car is older than 2008 then it should pass the mot .. if your car is younger that 2008 then it will fail .. any light will fail the mot.. any problems with brakes will fail mot .. wheels , steering will fail if its not right .. how ever if your car body is scratch or bend it should be ok .. best way to do MOT is to know someone who doest try to rip you off .. if you are in surrey or farnborough, aldershot, farnham, alton, ascot , reading then you can go to 4weeler garage in camberley .. they dont ripp people off .. they will show you problem if they find it stright away .. its easy 35 for mot ..

Alan Buchan says:
17 February 2020

Airbag light on is that a mot fail

David94cestria says:
2 September 2020

1998 Volvo S80 2.9SE with 135,000 miles on the clock and running perfectly is showing ABS light on continuously. Local repair shop has checked systems thoroughly and they are all OK. BUT they are unable to disengage the warning lights. As the car predates 2008 will it be an MOT fail? Any help ?