/ 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?


We have a 2012 Jeep Overland and it is displaying a message that the 4WD needs to be serviced. This is a common fault on the Jeep and is due to a faulty sensor. The Jeep otherwise completed roadworthy with all systems working as they should be working. I cannot see how this cna be a MOT failure although it is a warning message!

Surfer – According to the Intro to this Conversation [also dated 2012] “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“. So, presumably, a service reminder message is not one of the critical indicators that could fail the car’s MOT test.

They’ll argue that if it does fail you won’t know.

As a follow up to the warning light system as per my original post. We have a service contract with a franchised Jeep dealer and the service contract is per manufacturer’s specifications. It is a 2012 Jeep Grand Cherokee Overland Summit with 60k miles. Included in the servcei contract it states that in the event of a MOT failure it is insured for up to £750 of repairs.
Stranely there was no issue with it passing the MOT and when I collected it after the service the message Service 4WD no longer displayed and has not until today when it came back. I now suspect that prior to it going for the MOT they removed the message so that it would pass.
incidentally the vehicle was supposed to have either the 100k or 8th year service howeve they did an interim servcie and not the 100k service as we found out later. Therefore the service was not carried out to the manufacturer’s specifications. After a lot to to and fro’ing they have now agreed to do the correct service however as the warning is back up they may try and charge me for the repair. There is no issue with the Jeep and everything functions correctly so suspect an faulty sensor.
I am not sure where this leaves me now if they try and charge me for a repair to the 4WD system? Also how woudl I know if they frig the software to remove the fault and it shows up again in a couple of weeks time?

Here’s a site discussing the MoT requirements. https://www.motester.co.uk/mot-test-of-instrument-panel/ It may be the warning light you refer to does not constitute a failure. Maybe the service will be carried out when you return the vehicle but, if not an MoT issue, you may be charged for it unless it is part of a service pack.

Hi Surfer – Perhaps it would be worth subscribing to Which? Legal and getting legal advice. Jeep should be able to advise of whether the light being on constitutes an MOT failure. I suggest you ask head office and not a dealer. Alternatively an independent MOT station may be able to advise.

My driver’s side airbag is flashing and I’ve been failed on that one ? Can this be clarified ? Thanks.

It’s worth entering your registration number into this website and checking to see if there are any recalls, although you should have already been notified if there is a problem. If not you will need to have the airbag replaced.

Christine Towns says:
10 November 2021

My warning light comes on to say that a door is open . However it isn’t open . I ha enough been told it’s probably an earth problem .