Hi ladies and gents

I've got a problem with a 2005 Punto Active 8v that is extremely frustrating. I bought it a few weeks ago and it drove fine, a little underpowered as I was used to a 110bhp turbo diesel previously, but everything felt tight consider it being 8 years old and having 66k on the clock.

Then one afternoon, after a 25 or so mile journey with the Mrs and kids, I changed down into second for a tight corner and the car cutoff without warning. Initially, I thought I had stalled it but later found this wasn't the case. There were no warning lights at all when it cutout. However, the car would not restart because the engine immobiliser light was on. While waiting for the AA, some 15-20 mins after cutting out, the car restarted, showed no warning lights and ran perfect again.

The following day, the Mrs was driving and she changed down to go around a slow corner and the car cutout again with no warning. Again, the immobiliser light stayed on and the car wouldn't start. Some 15-20 minutes later, it fired up but this time the engine management light came on and stayed on but the car drove fine.

I returned it to where I bought it from and low and behold the engine management light went out. The garage tried to replicate the problem but couldn't. Also, they scanned it for fault codes and found nothing. A couple of days later, they tried to scan it again and three faults appeared, with the main one being something to dow with the ECU and immobiliser. They sent the ECU away for testing and it was deemed that although the ECU was not dead, it was showing signs of failure. They replaced the ECU, apparently, and I picked the car up.

The drive home was perfect until all of a sudden, shirt,y after changing down to third on a hill, the ABS light flashed, the power steering light came on and the engine cutout! This time the immobiliser light stayed on when the ignition was on and so was the power steering light and the ABS light occasionally flashed, too.

Also, I had the hazards on and the red hazard button flashed, the actual lights outside flashed and I could hear the relay ticking, but the green arrows on the dash were basically doing what they wanted to! Locking and unlocking the doors seemed to disrupt the hazards for a couple of seconds.

After trying to restart it, there was an occasional noise that I can only describe as being similar to a washing machine emptying but only fainter and less harsh. I'm assuming this is the fuel pump due to the immobiliser. 30 mins later, the car started, the engine management light flashed on for less than a second and it drive perfectly!

The garage is coming today to take it away and test again but I don't have much confidence in their fault finding abilities so if you fine people have any ideas I can pass their way I would be massively appreciative.

I forgot to mention that at no point had the temperature gauge gone past the normal operating temperature. While I have the car I am happy to have a poke around at it based on your suggestions but I have very limited tools and my technical knowledge is like that kf a ten year old!

Congrats on getting this far, but I thought I'd paint a decent picture for you!

maybe the 1.2 8 valve isnt for you mate even in these austere times?

id guess bad earth/short to earth somewhere

you need Autosparky on it not mech.

I'm sure it will turn out to be an earth fault. The issue (and the cost!) will be finding the earth.

You can begin the process by unbolting, scraping clean, smearing with vaseline and bolting up again the battery connections and the main engine earths -- one from battery negative to inner wing, one from the inner wing to the top of gearbox. There may also be a separate earth to the top of the ECU. All the earths on modern FIATs are black.

Thanks people. I've let the garage know, I'll let you know any findings in case people have as similar problem.

Earths were fine so they've brought in an auto sparky to take a look at the immobiliser.

Sparky says there's a fault with the body computer so it's been removed and sent for repair. Hopefully, this will sort it for good; public transport sucks!