Talk Morgan Forums Morgan Sports Cars Morgan Aero 8, 2012< Plus 8, SuperSports, Coupe & Aeromax Engine management light...

If I recall correctly the way it works is the sensor has a preset value in the programming eg xyz ohms - if the value of the sensor goes outside of that parameter it will illuminate the light - most manufactures add an additional parameter such as if the value is exceeded more the 15 times the light comes on - This prevents the light being illuminated by the parameter being exceeded by a minimal amount - that way the light SHOULD only illuminate when there is a real issue
not sure what Morgan have programmed in though

I agree OBD tester is now part of my toolkit .Get one that enabled the light to be reset not just read

Gajet

As others have mentioned, the light can go out on its own.
In my s2 It was clearly related to heat, and exhaust / cat temp as others have said - I let the car cool, then took it out for an itallian tune up, which invariably fixed the light...

I have been told that in order to comply with European regulations (and I think American regulations) a warning light for the mal-function of the catalytic converter that has been caused by the post-cat sensor can not re-set without intervention. I would therefore suspect an engine warning light that re-sets after a period may relate to some other condition.

Engine management light in my Maserati was always O2 sensor related. Disconnecting the battery, or a good blast would always sort it out. I think the Aero is often the same from experience. If the sensor has failed then it will not be rectified - that is certainly true, but if it is just acting up (which from experience they can) then its possible that this can be 'reset' through various means....

I don't want to point out the elephant in the room here. I do like the idea of the Italian Tune Up. I too have had the light go off of its own accord after it coming on in the Coupe.

My worry is that if there is an engine fault then taking it out for a blat may have an adverse effect. The fault may turn lethal for an engine part or worse in the event of a failure. In general doctors like to investigate before they cut.

Thats why it is best to have your own OBD 2 reader. At least you can tell what sensor is playing up. I have a cheap bluetooth model connected to my phone. Gives lots of real time information and I can be all "geekie" in the car s well.

Agree that I don't recommend the Italian tune up as a first recourse Equally I would point out that modern engines are incredibly reliable, the electrics that surround them - less so. With an OBD2 reader and a heathy sense of skepticism its possible to remain on the road and devoid of engine management lights for the vast majority of the time.

You can of course line the dealers pockets and run to them every time the light comes on, but as others have hilighted, O2 sensors and cat temperature are the main reasons these things seem to happen, and the solution to this is just a reset, a wait, or another journey.

The v8 in the Aero is not stressed. My 745i did almost 100k miles by the time I sold it. It was barely run in at that point, and was lugging twice the weight of the Aero, which uses the identical engine... Few aeros will do that mileage in their life, the likelyhood of a significant engine issue that doesn't involve loss of coolant or oil and therefore indicate itself spectacularly is I think pretty unlikely....

I got the amazing engine light as well.
In my case was "Evaporative Emission Control System Leak Detected (small leak)" promptly identified by my cheap Chinese ODBII Bluetooth reader and Torque App.
To get rid of it the fix was simple. Go to the dealer and have fixed a rubber tube that was broken.
I reset it once but a proper Italian tuneup brought it back immediately.

This is from a paper on the American OBD 2 standards. The system in other regions may not be so strict however you can see from this that if the fault relates to a "malfunction" of the catalytic converter, at least on systems intended to comply with the USA standard, the MIL light will not re-set itself. I have added the underline.



In some cases the number of cycles (trips or ignition on/off) may be less than 20, as low as 3, for the MIL light to go out for non-emissions related faults but the fault remains in memory for a period.

If anyone wants to wade through many pages of information there are explanations here in a reasonably understandable form of how the whole OBD 2 system works. Introduction to On Board Diagnostics (II)

Guys, I've been reading (and re-reading) all the comments and suggestions in this thread; and I'm coming around to thinking that maybe putting in a new (and hopefully, less sensitive) lambda sensor may not after all be the answer to my ongoing problem about the engine management light coming on so frequently!

I have already bought myself an OBD 2 which I will use to cancel off this light (which is in my books becoming a bit of a nuisance); but that will only be a temporary solution: That light will come on again and again unless a more permanent answer is found.

Someone [in this thread] mentioned changing the headers which should give an improved performance; but as I have a sports exhaust fitted (giving better gas flow but which has the unfortunate quality of the cat running cooler because of it) I wonder whether it would really make any difference after spending all that money and time.