Engine Management Warning Light

[derekpara]

I was under the impression that a dashboard engine warning light was an MOT failure item.
Now a knowledgeable and professional fitter friend of mine claims that this item is a fail only if it displayed in red . Any other colour, ie, yellow, orange etc does not constutute an MOT failure.

Can anyone give me a definitive answer, please ?

Cheers.

D

[davebro]

As I understand it the lights have to come on when the ignition is switched on & go off when the engine is started. Never heard that the colour makes any difference.

[gingejbee]

These lights are off or on...they may have different colours from different manufacturers, but if "on" constitute a fail.

https://www.honestjohn.co.uk/askhj/answer/104539/is-an-engine-management-light-an-automatic-mot-fail-now-

[davebro]

https://www.motester.co.uk/mot-test-of-instrument-panel/

[derekpara]

Oh dear. Thanks everyone.
D

[gingejbee]

Some years ago, I had this light come on a previous car and phoned the supplying dealer. Service manager told me to take the car on a "fast run" and see what happened. I did that, getting the car nice and hot and the light went out and never came on again!
Worth a try?

[Rationalist]

Generally, an amber light on the dash is advisory, suggesting the driver takes action.

A red light is a mandatory issue.

I don't have link for that. Just talking to car design engineers.

[derekpara]

Thanks, gingejbee, would be worth a try but car now in garage for a sensor change.
And thanks to you, too, Rationalist. I wish you could provide a link to support what you say. I refer you to both links provided in the earlier answers above.

Thanks again.

D

[pixie374]

My car handbook says the same as rationalist (no link either...), a warning light is amber and urgent is red. I don't know which affects an MOT though x

[davebro]

It doesn't matter about the colour for the MoT.

e.g. A red light might tell you to stop immediately or risk engine damage or brake failure.
An amber light might mean there is a problem with the airbags but the car can still be driven.

Both are MoT fails.

[derekpara]

Update and further question.
The garage ran an engine scan and subsequently renewed the knock sensor at a cost of £120 Parts and labour. Within five miles the light came on again but it was too late in the day to return to the garage.
They have asked for the car back for further checks and it will going in next Thursday. Today, the warning light went out for about an hour before showing once more. To my inexperienced mind I hink it could either be a wiring fault or the car/sensor is going through a period of readjustment. The sensor is of good quality.

What redress do I have ? Pay the cost of the sensor but not the labour, but pay for,say, any corrective wiring work ?
I have had work done by this company several times before and the service has always been good, and fairly priced.

Any advice welcomed.

D