Technical Fiat Stilo 1.6 - Car Security issues

[The Brownman]

This question has been posted many times, but I haven't found a definitive answer for my situation. So I thought I'd ask. Here's the issue -
The other day I was in stop/start traffic and every time I let off the throttle, the car was shaking like mad, as if it wanted to stall. So I changed into 2nd gear and the issue persisted but was more violent. Then the car just suddenly cut out, tried to turn it back on while rolling but was having none of it. Crawled my way to the hard shoulder and had a few issues come up on the dash (I'll attach pictures). Got recovered, taken back home and tried to turn the car back on the next day. It fired up nicely and was idling well. But, as soon as the temperature got to around the second line, it cut out and wouldn't come back on. Now the issues that come up on the dash are:
Car Security Loose Connection
High Coolant Temperature

I've replaced the thermostat and temperature sensor for brand new ones, hoping to eliminate the high coolant problem, but considering the car won't start, there's no way to check it.
Now whenever I turn the ignition on, there's a loud ticking/clicking noise coming from the relay unit/fuse box in the engine bay. The red relay which is in the bottom right hand corner of the unit is creating the noise and whenever I take it out, it stops ticking and the car security - loose connection problems clear from the dash. But the car still won't turn over and just keeps displaying high coolant temperature. So then I'm back to square one again. I've checked the ECU and cleaned it up, I've also checked the D4 connector and it looks fine. I'm in desperate need of help as this is my only mode of transport. So any help would be greatly appreciated

 

[jatkinson]

Your body computer that gray box were all the relays are in will have got water in, I got that loose connection error, took that body computer apart to find that water had got in and started to corrode the board so cleaned that up and every thing has been good

You might need to get your car plugged in to clear the faults, or it might go sway after 3-4 starts

 

[The Brownman]

Your body computer that gray box were all the relays are in will have got water in, I got that loose connection error, took that body computer apart to find that water had got in and started to corrode the board so cleaned that up and every thing has been good

You might need to get your car plugged in to clear the faults, or it might go sway after 3-4 starts

Lovely, thank you mate, I'll try that now!

 

[Davren]

There's a guide to cleaning/drying the engine compartment fuse box here: https://www.fiatforum.com/stilo-guides/313986-how-clean-dry-out-fuse-box-near-battery.html
.

 

[The Brownman]

Right, great news. Fixed the problem in the old whip and turns out it was just a faulty earth wire. Rerouted the earth from the ECU to the negative terminal on the battery and everything works fine now. From what should've been a £5, 5 minute job, turned out to be a £80, 2 day job. Oh well, at least it's all sorted and I've got a brand new thermostat, temperature sensor and coolant!

 

[richydraper]

psst jatkinson... the BC is attached to the back side of the fuse box behind the dash, not in the engine compartment, if you get water in the BC you have MUCH bigger issues... The BC is the bit that you connect diagnostics connector to.

the part you're on about is just the engine fuse box

 

[Stilatos]

to me that reminds me of my problem with the ecu with the temp randomnly jumping to high temp. i found out after tapping the ecu with a screwdriver it did this hence the ecu was problematic. You should write in the greek fiat forum to help you also we have a great diy section

 

[onfire_82]

psst jatkinson... the BC is attached to the back side of the fuse box behind the dash, not in the engine compartment, if you get water in the BC you have MUCH bigger issues... The BC is the bit that you connect diagnostics connector to.

the part you're on about is just the engine fuse box

Been there - blocked drainage hose from sky roof ended up with dripping down the A-frame and pooling around that area. Causes a lot of gremlins to appear.