Warning lights on? Your car will fail its MOT test

Wig

Check your cars now and note what your fully operational lights do on start up.....

If one should light up permanently you will have a better idea of which bulb on the dash to link it to...

But some of these lights go off independently of any other like the ABS light so a savvy tester will still fail it. On mine the airbag light goes out a fraction before the ABS light.

corbyboy

We seem to have gone a bit off track here. The OP started by talking about his traction control indicator light failing an MOT. We seem to have extrapolated this to mean that any warning light will result in an MOT failure.

Can anybody confirm or deny will the general "check engine" light being on result in an automatic failure?

mikey72

The ones that will be tested are
　
Main beam warning light
Illumination of malfunction indicator light (MIL) for electronic power steering, electronic stability control, electronic park brake control, brake fluid warning lamp, tyre pressure monitoring system and air bag/ pre-tensioner

http://www.dft.gov.uk/vosa/repository/MoT%20-%20Issue%2050%20-%20May%202011.pdf

Wig

There will be also the ones already tested eg ABS,
there's a comprehensive post further up of the new ones, it would be nice to have a full list of testable warning lamps, and which ones are not to be tested.

"During decelerometer test if the vehicle deviates from a straight line when parking brake applied"

A) How are they going to test that?
I bet there are vehicles out there which from new would not be able to pass such a (useless) test.and no amount of repairs will make it pass.

Road_Hog

Gloomendoom wrote: »

This has all been introduced to comply with EU directive 2010/48/EU and is a direct result of the UK signing away its sovereignty at Maastricht.

If you think it is silly and unnecessary, then write to your MP.

Ah, good, at least someone else understands why this has happened. It's to bring us in line with the new EU MOT and the second stage is to switch to two year testing.

http://www.motester.co.uk/MOTTrade/MOTIndustryNews.aspx

BTW, don't write to your MP, he will do nothing.

ohreally

mrcow wrote: »

We've got a "check engine" light that is on permanently.

Not necessarily. The warning lamps that will cause the vehicle to fail are on a prescribed list - simply having a MIL showing is not a fail in its-self.

Interestingly non standard trailer sockets will be a reason for failure. I know an old chap who has wired his socket to prevent friends and family helping them selves to his trailer.

Gloomendoom

Road_Hog wrote: »

BTW, don't write to your MP, he will do nothing.

I disagree, if more people wrote to their MP's, they would do something. Otherwise they just think we are all happy with all the daft legislation. No news is good news.

sparrer

mrcow wrote: »

We've got a "check engine" light that is on permanently. It doesn't do or mean anything according to the garage. So will this fail too?

My 'check engine' light has been on for over a year, on and off. Took it to my garage, they ran diagnostics but found nothing so turned the light off. A few months later it came on again, they did every test on the car I should think is known to mechanic, still no reason found so they turned it off again. The third time it came on one of the mechanics said he had one the same, and I was advised to stick a bit of chewing gum over it!

A bit concerned as my car is 10 years old and I can't afford hundreds to have it fixed at the main dealer, and certainly can't afford a new car!

atrixblue.-MFR-.

sparrer wrote: »

My 'check engine' light has been on for over a year, on and off. Took it to my garage, they ran diagnostics but found nothing so turned the light off. A few months later it came on again, they did every test on the car I should think is known to mechanic, still no reason found so they turned it off again. The third time it came on one of the mechanics said he had one the same, and I was advised to stick a bit of chewing gum over it!

A bit concerned as my car is 10 years old and I can't afford hundreds to have it fixed at the main dealer, and certainly can't afford a new car!

a car that old is more likely to be running EODB software instead of the ODBII. more than likely a few ground points have got rusted and is causing a weak contact throwing up a EML, it only needs to come one once and will probably stay on in older cars, once erased the car then rescans, when you hit a bump the contact is interrupted in the weak ground point and throws the EML back up ive had a few pugs do this especially around the ECU where there allot of wiring and ground points one even had an arching live wire sparks hit the ECU wich shoked it into resetting the whole ECU wich caused a dash fault with the speedo's working then not then working then not going down the road.

its good for a car of 10 years plus to be checked out for rotting wiring some fuses and relays changed, all the ground points checked for rusting over etc.

jackieb

Horizon81 wrote: »

Good for you! However, there's plenty of excuses, like the fact that many of these error codes relate to the sensors being faulty, rather than a genuine problem. It's laughable that the sensor that is supposed to alert you to a problem can itself fail and lead to a warning light, despite there being nothing wrong with what it is supposed to monitor. Far too much electronic intervention these days.

We have a Mercedes with just over 30k on the clock. Always been serviced regularly at the main dealer. Two months after our last service the warning light came on saying the brake fluid was low. My husband filled the window washer bottle and the light has stayed off ever since!