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

I seem to have the engine management light coming on (and staying on) with alarming regularity!

For the first few times after taking delivery, I brought the car into the dealership to check it out; and each time, they found nothing amiss and the Max drove perfectly well. Then subsequent times after that, I just ignored it and the car still drives like a dream!

The question now begs: is the sensor too sensitive and needs changing? If anyone has a similar problem, I'd like to hear from you and what you did to put this fault right.

I would suggest buying a OBD 2 reader which costs about £10-£30 depending upon where you buy it. you can then read the fault code(s) and decide if its safe to use the car. If its the same code/sensor then I would get it changed.

Neil

+1:

I had an over sensitive lambda sensor, one of the 4 on a roadster. Kept on triggering the yellow engine light. Williams replaced if, not been a problem since.

Engine lights are triggered by data fed to the car computer. All Morgans have "custom", ie non standard exhausts. False triggers from lambda sensors are a common feature of modified exhausts.

You can get a nice little device that plugs into the OBD socket and talkes to a smart phone. Can't remember the details, will dig them out. But you can also get loads of mindlesssly interesting data out as well as cancelling lights....

My roadster came with this fault FROM THE PRODUCTION LINE SIX YEARS AGO!---Now despite going back to MMC TWICE to have the ECU returned to the supplier by the factory, the fault was not rectified or it would seem even correctly diagnosed. So it looks like it could have been the lambda sensor all the time.

For me the car which has just been recently serviced drives very well---BUT when the engine management light appears----my heart sinks along with I am afraid my opinion of MMC. Maybe MMC should throw in an OBD II reader AT THE TIME OF PURCHASE if their efforts of harmonising the exhaust with the engine is so hit and miss.

Some info on this thread
http://www.talkmorgan.com/ubbthreads.php/topics/158156/1

I had a good one on the "new" Coupe this week. Mark Baldwin worked it out without touching the car. Apparently he acts as a remote diagnostics unit ? Spooky 8^)

If I overfill the petrol tank it puts some in an overfill unit and the vapours sets of the fume sensor. If I try and put more in after the first click of the pump it causes it. Once I go below 70% and leave car for a bit then next time I restart it does not come on.

I don't try and put anymore in after the first click now. Let's not talk about the accuracy of the gauge shall we ?

Guys, you've been a great help with your suggestions! Thnx so much!

All blame points towards the lambda sensor which I will look into after the Xmas break. And if that sensor is replaced and still the problem hasn't gone away, I will be looking into getting an OBD 2 reader!

Cheers!

I had the same problem when my plus 8 was 4 months old. Fulty sensors changed and now ok.

Thnx Deano! Evidence is mounting against the prime suspect: faulty sensors!

The main problem is that anti pollution regulations require a sensor after the catalytic converter to check the correct functioning of the cat. The alteration or removal of the cat and/or the post cat sonda lambda sensor is contrary to the regulations in most countries. If the sensor detects an anomaly that lasts for more than a short period (once the engine has reached operating temperature) the engine warning light come on and stays on, in theory, until a workshop has checked the car. Fortunately with the help of an OBD II reader we can check the error code and re-set it ourselves. Obviously if it is not a "harmless" error it should not be cancelled. Some error codes will re-set themselves when the condition no longer exists or the engine is turned off and re-started and others, such as the "malfunctioning" of the cat will stay.

For correct functioning of the cat it needs to get extremely hot and this requires it to be fairly near to the engine. Sports exhaust systems, that are designed to optimise the flow of exhaust gasses, have longer exhaust manifold tubes and this often means it is difficult to raise the cat to its working temperature.

In the absence of an OBD II reader, if absolutely certain it is just a problem with the sonda lambda sensor the ECU can usually be re-set by disconnecting the battery. Most modern ECUs have a "learning" function which adjusts somewhat to the driving style of the driver so it may take a few miles before it completes this process of calibration following a complete power off re-set.