Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Ugh...check engine light is on

Hey Nick,
Thanks form the flowers. Yes, the wild south of germany is a very nice region for all kind of actions: hiking, biking, motorcycling, morganing, river swimming, climbing, ...
And within a 90min driving distance you can reach the central swiss alpine region :-)

If you gain some additional informations about the ECU error(s) or need further support just let me know. After facing a lot off odd constellations with my own Threewheeler I had to deal a lot with the S&S documentation and the complete fuel system.

Best regards
Kurt

My mechanic told me that incorrect exhaust back pressure can cause the light to come on. I observed on a cross country trip that when one exhaust cracked the light came on. When the second exhaust also cracked the light went off. I attribute this to the ECU being unable to adjust the timing to be correct for both cylinders with only one exhaust cracked, but with both cracked it was able to adjust the timing. That's just my deduction but I am not a mechanic.

I would be curious which error would be reported in such a constellation by your ECU. I would expext error codes P0170 or P0173 (fuel adaptive map maxed out), as there is only a certain corridor foreseeen to adapt the fuel amount based on the standard mappings.

Ding ding ding ding! Winner!

P0170 or P0173 it is. Not entirely sure what it means. Maybe it is the back pressure issue?

Hmm ... DTC's P0170 / P0173 can be caused by a number of constellations. They are popping up if something related with the O2 sensor values is not matching what is expected.

People would normally assume, that it is caused by defective or malfunctioning O2 sensors. But in most cases this is not true. The O2 sensors are being clearly destroyed/poisened by leaded fuel, but at least in europe you will find that kind of fuel at no regular pump gas station - IMHO you can find it at airfield (AVGAS).

More likely are wiring issues (bad contacts/rotten connectors) or damaged cables, but if the cables are looking fine this is not so likely as well. You may unplug the connectors and do a visual inspection against corrosion. As Morgan is using super seal connectors the pins are most likely in good condition.
DO NOT APPLY contact spray - according to my fuel injection experts this might have a bad impact on the signals!
In doubt you might messure the voltage signals at the sensor, which must be done in hot conditions - DO NOT burn yourself.
The voltage levels are mentioned in the S&S Pro Tune manual.

In my experience a likely cause of those error codes are leaks (vakuum leaks on the intake section - unless your intake header or seal is damaged, this can't be seen at the S&S engine, due to the overall construction (no plastics, just solid metal), or leaking exhaust pipes/headers - cracking headers at the head connector or leaking tube seals ahd been reported a number of times). In your case I would assume this is the case at your car.

Just to be complete on this topic:
You will find this errors as well, when you are facing odd constellations regarding the fuel pressure at your injection rail, which should be around 58psi / 4bar. In case of an sick fuel pump, blocked fuel lines/filter, poor wiring contacts or squized wiring cables, or a dying ECU (the ECU seems to control the fuel pressure as well).
The fuel injectors could be clocked.

To summarize all influecing facts one could say:
Everything, which is causing a weaker (or fatter) mixture as respected by the ECU algorithms might show these errors.

THE ECU has quite a number of map fields defining when and how long fuel is injected to match the closed loop targets (emissions), depending on throttle position, vakuum, barometric pressure, engine & air temp, rpm speed. The maps are existant for each cylinder as the engine is normally installed in driving direction (front/rear cylinder - rear cylinder running hotter).
In conjunction to these base maps the engine is "learning" an adaptive map by monitoring your specific engine behavior which is used for fine tuning the values. (Note: the adaptive map can be purged in Pro Tune "advanced mode" and will then be selftrained over the next hours of operation. Puring the adaptive maps will first result in a more poor engine mood until the training is finished).
For the adaptive map there is a limited range of tolerance. If your engine is exceeding the adaptive limits these errors will pop in.

Oh boy ... I know this is dry stuff, but no rocket science. I hope you managed to read/understand until this line :-)
If yes, things might be now more clear to you

Thanks for the explanation spelunx, that helps a lot! I think I understand all of the possibilities. I can check the connectors when I get home tonight.

Is there some advantage to purging the adaptive maps? A chance maybe that the self training went wrong the first time?

I would recommend purging the adaptive map only, if all other inspections did not give a clear indication, what might be the reason for an poor engine running.

In most cases there is a reason for a displayed engine check. Deleting the learned adaptive map will not cure the cause of the problem itself.
I did so, after having check nearly all possible causes at my car and being unsure, if the adaptive map trained itself bogus engine constellations.

In the end it resulted first on extremly poor idling & starting and a very lean mixture on one cylinder, which resumed to the original behaviour after having driven a number of hours and passing through all levels of engine load to teach the ECU.

But as the root cause had been a defective ECU which suffered problems on nearly all involved engine sensors and throttled the fuel pressure down to about 40% of the correct level it didn't help at all.

My last joker had been humbling to the next dealer and swapping for investigation purposes the ECU against one of a running car. With this one it run absolutely brilliant again, so it was proven that the ECU was damaged.

This is not a very common failure. ECU's are normally only destroyed by overvoltage problems (shortcircuits, voltage peaks, ...) which normally domnot occur.

My personal suspect is, that S&S had a problem in the manufacturing process of the electronics components (e.g. Oxidized soldering pads, weak soldering, etc.)
I will ask the dealer, if he still has the old ECU and would mind returning it to me, so I could ask my SMD manufacturing experts in our plant to open the decive for a visual inspection. (We are manufacturing automotive electronics since decades)

Adaptive map purged....just in time for days of horrible weather. I'll let you know how it goes after some driving. Luckily I'm only 400 miles from the first service, so if it doesn't work I can have them look at it at the same time.

Hey Nick,
So finally you got already a little common with Pro Tunes - very cooL. I am pretty curious about news related to your car.

BTW In case that anyone is confused about the operating systems supported by Pro Tunes:
S&S ist mentioning just Win7/8/8.1, but is is running fine under Win 10 as well :-)

I would highly recommend to review the available Pro Tunes documentation. It is well structured and explaining the algorithms which are driving the ECU in detail including flow diagrams for the procedures involved. It is a source of valuable informations. If your are able to think straight forward you don't need to be an IT expert to understand quite well what the job of the ECU.

I have a 2014 and the USB port seems to be missing, possibly with a blank plate riveted over it.

In cases like that, do you just find a cable with an OBDII end?