Sorry this is another post on the dreaded motor control system failure message. I've read lots of posts regarding the errors, and when I think I've found an identical issue, upon further reading it turns out to be slightly different. My car by, the way is an 04 GT 1.9 JTD.
Anyway a little history. I got the mcsf message and light a few months ago, and although I don't see any issues with loss of power, excessive smoking or car engaging limp home mode, the light stays on permanently.
I followed the advice from a few threads on here and cleaned out the egr valve, however didn't go as far as cleaning the solenoid. The light remains on.
I've recently spent a small fortune sorting my windows out and asked my garage to look into the problem, their computer threw up a code diagnosing a faulty MAF, which has now been replaced. Driving home from the garage last night, the mcsf appeared again. Tonight I took my car back to the garage, they plugged their computer back in only to tell me there are now no error codes (apart form a 1298 (???) consult technical manual, which they said appeared all the time). The error for the MAF is now not there, and they can see reading from the MAF in their software that would suggest this is now working ok......it wasn't before.
The mechanic has now suggested I replace the EGR valve, I told him I'd cleaned this before, but he was quite convinced this would sort the mcsf out.
Apologies for the long thread, but I can't really afford to just go buying an EGR valve only to find that is doesn't sort the problem. Apologies too if I've missed a post that explains my problem in great detail, but I thought I'd ask and see if anyone can help.
Hope this all makes sense, and thanks in advance for any replies........