Hiya :wave:

I'm asking this on behalf of my Mother In Law. She has a Seicento Sporting which has had a problem with one of the warning lights since she bought it. I think it's the injection light/engine warning light.
It comes on at random when it's started up, it doesn't go off when driving at all only when the ignition is fired. If it is on when fired up then it will stay on IYKWIM until its turned off, then it may still be on or it may have gone off.
Anyway! When it's on the engine idles very lumpy, it isn't very powerful going up hills etc and it drinks petrol.
She took it to FIAT for it's timing belt replaced last week and got them to put it on the machine. I went with her when she picked it up and the guy told her that the ECU is recording 'internal errors' and she would most likely need a new ECU. I asked the guy about the oxygen sensor and the MAP sensor and he said that the o2 sensor was 'iffy but not enough to be recording failure' so he then told her to take it back in a few days. So she took it back, again I went with her, and the light was off at the time. A young lad from the garage took it for a drive and came back saying it was okay - he 'wiped the ECU' apparently but four hours later the light was back on :bang: Again she took it back this time when the light was on and they looked at it again and said possibly coil number one wasn't working properly
She has two weeks warranty left from the (non fiat) dealer she got it from but until he knows for definate whats wrong with it he won't do anything for her, which is understandable.
This light/problem is ruling my MIL's life, like mental torture. She is getting the way that she doesn't want to take it out anymore.
She has tried some things herself like :
putting optimax in (the light went off) but came back on after about 4 hours.
Wiggling the HT leads, one wasnt seting properly again light went off but came back on after 4 hours
It's so damn annoying as it is so random

So does it look likely she needs a new ECU ? Apparently, they guys at FIAT said they had tried to reload new memory onto it but it wouldn't accept it?

As a side note, I have a mk1 Punto 1108cc doing nothing, would the ECU from that go on the Seicento 1108cc?

Many Thanksfor reading all that

the immobiliser will stop you swapping ECU's,also is the MS an MPI?
using loads of fuel and poor running sounds like a lambda problem.
if one of the coils isnt working then you should have at least on spark plus not sparking.
remove each HT lead in turn along the row using insulated pliars or the like.when you remove it the engine should run rougher.if theres no change then theres no spark there.
once you identify that you can swap the colis over to see if the problem moves to another spark plug as you would expect then you know that coil pack is faulty