Hello, First time on the forum any advice would be apprieciated , My son's 1.2 Stilo has given up, it died it stages, electrical gremlins (lights working intermittently) then all dials on the spedo stopped working next the power steering went and now it will not start (also loads of condensation inside running down the windscreen?) , someone looked at it and said the ECU was breaking down. I have the following error codes P0105 P0420 U1700 U1700, the car is a 2002 paid £1000 for it, would like to know from people on the forum if it is even worth getting it fixed with these error codes or is the next step the scrap yard, Thanks Pete

Hi if you can get a ecu it shouldn't be much but make sure that you get a plug and play one or you will have to take it to a dealer to get re programmed to your car
If I was you I would stay well away from going to a mechanic as they will most likely charge you £350-£800 just for a new part without fitting and you will then have to take it to fiat to get programmed
There are company's online that you can send your ecu to they normaly charge £35 to look at it if it needs fixing the price goes upto £120 plus parts if you use this option then your ecu will already be programmed to your car
I would say yes it's worth a try to fix it
If you buy off ebay make sure part numbers match on the unit

Hi Pete, Welcome to the FF.

U1700 is a CAN connection error between the Engine Management ECU and the Body Computer ECU. Which ECU does "someone" think is breaking down?

Most of the problems you describe can be caused by a discharged, poorly connected or faulty battery. Describe what happens when you switch the ignition on, and also, when to try to start the car.
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Thanks for the replies, the guy who looked at it did not say which ECU it was, He did not even look at the error codes (don't think he fancied getting involved in the work to be honest) I borrowed the OBD reader and got the codes myself. When the ignition is on I can't tell if anything is happening because the whole of the display is dead, the engine does turn over but never starts. What sort of job is it to change the ECU's if they are plug and play as mentioned below, the guy who came round said it was a nightmare job dash completely out is that correct?.

If the engine is turning over normally, it would suggest that the battery and engine earth lead are OK, however as you've had several other electrical problems it could be a body earth fault. Check the body earth lead connection on the chassis leg under the battery box. It's quite difficult to get to so you could (for test purposes only), connect a thick wire from the battery negative terminal to a clean bare metal part of the body.

The engine management ECU is located above the engine close to the battery. Very easy to get to. The body computer ECU is attached to the back of the dashboard fuse box. You would need to remove a few plastic panels to get to it. You don't need to remove the dashboard.

However, U1700 is a CAN connection error between the Engine Management ECU and the Body Computer ECU. The clue is in the word connection. It doesn't necessarily mean that the ECU(s) is/are faulty. Check the earth connection between the engine management ECU and earth (2b in the diagram below). Also, with the ignition switched off, disconnect the 2 connectors (1a & 1b) from the ECU and check if any of the pins are lower than the others. It's possible that some of the pins could have been pushed through the printed circuit board inside the ECU. Next you would need to check the 2 CAN wires (one black/pink, one white/pink) for continuity between the 2 ECUs.
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Thanks very much Davren, from what you say it certainly sounds like it is worth looking into repairing before I scrap the car, I will try the below and let you know how I get on, thanks again pete

I just started getting a similar problem, my car will start to kangaroo whilst driving then eventually cuts out. When I switch the ignition back on I have the car security light on the dash but with no message to it. Everything still works when I switch on the ignition - radio, AC, windows etc. but when I try and start the engine it will only turn and wont fire. When I gave up on it (it was 2am coming home from work) I decided to disconnect the battery and leave it in the car as I continued the rest of my journey on foot, hoping the system resets itself overnight. I returned to it the next day, connected the battery back in and turned on the ignition. The car security light was gone so I went to start it and it did first time. It ran fine for a couple days but its just done it again on my way to work! At least this time reached my brothers place out of traffics way and a 10 minute walk from work. Ive disconnected the battery again and will reconnect it when I return from my sleepover in work tomorrow morning. I dont know whats causing this at all, any suggestions?

Mark

These cars are prone to all sorts of weird problems caused by dodgy batteries. My son struggled for two years with his Stilo before I fitted a new battery and it's been 100% reliable ever since. The old battery was passing all the usual tests and led us on a merry dance before we decided to change it out of desperation. Symptoms were random error codes and failure to start.

my stilo was doing some crazy stuff when i changed gearbox, stalling, lights , dash going crazy and others. being not bad under the bonnet as i changed gearbox myself i had a butchers and turned out i didnt tighten the earth lead up properly to the gearbox. a little parp parp later and a run round the block and everything is dandy