Engine Management Light and MOT

[Tornado15]

There seems to be a lot of conflict when I search for this online.

Will it be an MOT fail if the engine management light is on?

[Superleg48]

https://www.pistonheads.com/gassing/topic.asp?t=18...

[The Rotrex Kid]

Yes it’s a fail.

[The Rotrex Kid]

[stevemcs]

Yep its a fail, get yourself a cheap code reader, scan it and see how long it stays off for.

[blue_haddock]

stevemcs said:

Yep its a fail, get yourself a cheap code reader, scan it and see how long it stays off for.

Or just actually fix the fault....

[Skyedriver]

Might be something very simple, the EML on my wife's old Suzuki used to come on if it rained heavily and she drove though a puddle, think it was water on the lambda sensor

[Tornado15]

blue_haddock said:

Or just actually fix the fault....

I have had it looked at but the garage couldn’t find an issue so replaced the sensor. The light has since come back on again.

[M_A_S]

What age is the car?

[Riley26]

I have a 51 plate suzuki swift that passes with the engine light been on been on for year. But think its OK for post 53 plate cars. Not sure to the reasoning.

[texaxile]

Tornado15 said:

I have had it looked at but the garage couldn’t find an issue so replaced the sensor. The light has since come back on again.

Then they didn't look hard enough and are lying to you. A faulty sensor will ALWAYS throw up a code, be it pre cat, post cat or whatever, so unless they had a specific code for the fault, they wasted time and your money.

Get your money back, give them some st and tell them they should plug in an OBD reader, get the code, cross reference it, which will give them the fault and fix it. An EML light throws up a fault code regardless, it is just a matter of reading it and addressing the issues.

[Aiminghigh123]

As someone else said get a reader from eBay and reset it see if it stays off.

My old Saab kept throwing EML light for SAI pump that was £600 to replace and was only on the 2003 cars. Just reset it at MOT time.

[mattman]

Alternatively, disconnect the battery for around 20mins, that usually clears the whole lot out

[stevemcs]

texaxile said:

Then they didn't look hard enough and are lying to you. A faulty sensor will ALWAYS throw up a code, be it pre cat, post cat or whatever, so unless they had a specific code for the fault, they wasted time and your money.

Get your money back, give them some st and tell them they should plug in an OBD reader, get the code, cross reference it, which will give them the fault and fix it. An EML light throws up a fault code regardless, it is just a matter of reading it and addressing the issues.

Not always that simple i'm afraid, they will give you a pointer although not always in the right direction. I would scan, clear the codes drive and then see what comes back then work from there.

[BERGS2]

My old LPG Pathfinder went through every MOT with the EML on.

(Pretty normal for an lpg converted car)

Didnt realise age was a factor in the passing of the test

Bergs

[Rozzers]

I thought it was a fail, a friends Brera fails on this every year, so he gets it warm the next day, I reset it, he drives to the local centre, guy quickly checks the lamp goes on and off and that’s it.

Comes on again in about 30 minutes, it’s cam chains or sensors, more than the car has been worth for years, emissions are still OK

[Drawweight]

My 208 EML comes on intermittently. It can stay on or off for months.

I had the codes read and it’s the cat not running efficiently.

At 125k I’m not surprised but as long as it keeps passing it’s MOT it won’t be getting replaced.

Most times it’s been off when the test is due but anytime it’s on I just get it cleared.

[Charles Sweeney]

Just go straight to the MOT manual. No debate then. Someone posted a screenshot above. Here's a link to the relevant section:

https://www.gov.uk/guidance/mot-inspection-manual-...

In the main it's post 2003 vehicles that are checked for it.

I run MOT Stats. I link the fail reasons directly to the MOT manual, which is fully online now.