This is a strange one

Veloce

Hi all,

I have sometimes being getting a 'motor system control failure' warning just after starting the engine my Alfa GT, it displays and then goes out after 5-10 seconds. The warning light never triggers when driving, only just after starting. Ive done a bit of research and this warning, can be a number of things; lambda sensors, MAF, crankshaft sensor etc.

Anyway I brought my car to the Alfa indy to run a diagnostic test, as the warning had began to reappear everytime i started it (it had not come on in 2 weeks). Usually when this warning is triggered, a fault code is stored in the engines ECU. However the results of the diagnostic test showed that no fault codes have been stored as a result of this warning.

The car is driving perfectly with no issues- no engine power lost, all electrics are working.

Has anybody has a warning light triggered before with no fault generated? Any ideas what could be triggering this warning light?

murphyebass

I have a GT too and have had this problem so....

My guess for whats its worth is it could be the EGR valve clogged with crap.

Try getting a fuel cleaner.

Get the car down to say a quarter tank left of fuel left, lob in a good dose of the cleaner into the tank.

Now get out on the motorway and through the gears push hard enough up 3000/4000rpm getting the boost to kick in and moving to the next gear, etc.

This should if the EGR isnt too clogged clean it out a bit and reset the monitor system control failure message your getting. Mine was intermitant too btw.

It worked for me. Failing that get an indie/alfa mechanic to have a look at the valve as it might need replacing.

Again just a guess and worth a try before going to a mechanic as it'll only cost ya what about a fiver for a thing of fuel cleaner. Think I used red x if I' remember correctly.

This wasnt me just randomly doing this btw. I rang my alfa mechanic who advised me doin it before bringin it into him.

Nonoperational

How old is your battery? A dying battery causes MCSF in Alfas. Loads of threads on Alfaowner about it. It would be my first port of call especially if it happens when you first start the car (battery possibly at weakest) and also because there are no fault codes stored.

cjt156

Maybe I'm missing something but how would a fuel additive effect a clogged EGR? Exhaust Gas Recirc systems relieve gas pressure from the crankcase and reintroduce the (supposedly cleaned) gases to the air intake.
These gases never come into contact with the fuel system until they reach the compression chamber and are burnt - along with the fuel additive.

The fuel additive never comes into contact with the EGR.

Veloce

Sorry I should have specified in my original post, its a 1.8 twinspark not 1.9 diesel. So no EGR issue.

I believe the battery is still the same one from new. (4 years old). I spoke to the alfa indy and suggested that could be the problem but he maintains that other warning lights would also be affected on the dash (usually), such as airbags etc.

The indy (Gerry in Ti autos) checked the fuses too, no issues there. Fault codes are actually being recorded though (fog light relay due to my botched attempt at changing the bulb!), so its not like the ECU acting up by not recording faults.

Nonoperational

In my experience no other lights showed up on the dash. Just the odd MCSF. The fact that it happens every time you start the car is a bit suspicious but I'd still think it's the battery.

If the MCSF is coming on for a genuine fault it would record a fault. Just changed a battery in the girlfriends 156 on Sunday because it was throwing random MCSFs, perfect again since the new battery went in. It was the original battery too, 8.5 years in the car!


I could be completely wrong too, but I don't know if there's any point paying people to diagnose a mysterious problem that doesn't record any code when the battery is known to cause this issue.

Veloce

gpf101 wrote: »

I could be completely wrong too, but I don't know if there's any point paying people to diagnose a mysterious problem that doesn't record any code when the battery is known to cause this issue.

Yeah your right. The diagnostics can be expensive.

I meant to say also, the light came on about 2 weeks ago, for about 4-5 engine starts over the weekend, Then it didn't didn't appear for 2 weeks until now. So its a bit sporadic!