Hi All,

Was driving on the way to work today and while at some traffic lights received a warning message from the ECU saying "Loose Connection". All the dials on the dash then died in unison. Fortunately the engine was still running absolutely fine so I thought I would risk the short journey to work.

On the way there I found that none of the electrics were working e.g. no indicator, no wipers, no central locking.

I feared the worst and as expected when I got to work and turned the engine off it refused to start back up again.

I've read a few posts on the forum about crank sensor faults and D4 connectors but being a bit of a car newbie was not sure if it could be related or not.

Any ideas or advice would be much appreciated!

Many Thanks,

Jamie

FYI: The car is a 1.9 JTD 2002 3 Door Stilo

re: Won't Start & Loose Connection Problem [ECU bad contact]

Im not very technically minded

Best to wait and see what all the other better ones then me think.

Glad im not the only stilo driver with prob's at the minute lol

re: Won't Start & Loose Connection Problem [ECU bad contact]

I know what you mean!

I do love my car but it is getting a bit of a habit with dodgy electrics and warning messages (I had the airbag warning light about a month ago until I found a guide on this forum to sort it out).

Oh just a bit of added info. I read some other posts with similar symptoms to mine however it seems most people would leave the car for a bit and try again and the engine would start.

Mine on the other hand is definatley a no-goer as I left it for about 4 hours and got nothing still.

re: Won't Start & Loose Connection Problem [ECU bad contact]

My car seems to have a problem with the turbo whistling to loud like it is a lorry.

Makes it sound quite sporty and beefy actually like it is fitted with a dump valve

However it needs sorting (lucky for the warranty lol )

I got back at about 6pm, and went out to see what it was like a few hours later - still the same

re: Won't Start & Loose Connection Problem [ECU bad contact]

I would recomend you check the solder in the engine bay relay box as i had a similar problem with the car cutting out before and loose connection kept apearing on the dash. I discovered that the solder between the relay that sent the signal to my fuel pump had broken. It cost £85 for the replacement relay box complete with new realys (for my jtd stilo). Hope this steers you in the right direction,

re: Won't Start & Loose Connection Problem [ECU bad contact]

Crank sensor symptoms are
intemittent or total not starting+ loose connection warning but dashboard all working as normal

Loose connection= lost connection=open circuit=bad connection or even fuse gone

Losing wipers and indicators + "loose connection" = open circuit
so check for bad connection particularly at the battery and battery earth where it meets the engine. Remove and clean all large fuses one at time in the engine bay. Check D4 connector (disconect+ spray+ carefully replace)

If it's totally dead then that's a bit easier than intermittent fault as you can trace where the power stops.

A1 Battery
B1 Body computer
H1 ign switch

Check and inspect everything in the circuit that leads from the battery to the body computer and ignition. Check those big jobby fuses close to the battery B99 panel in the diagram here
Thrill a minute

re: Won't Start & Loose Connection Problem [ECU bad contact]

Many thanks everyone for your advice last week.

I now have an update on the situation....

I got a mechanic to look at the car and after having a quick look over numerous connection points (around the battery and the ones to the right of the steering wheel in the little compartment) he found no obvious loose connections.

Before looking at any of the electrics in any more detail he tried disconnecting the car battery and left it for 10 mins before reconnecting it. This seemed to have the effect of resetting the ECU and the car started up without a problem!

Unfortunately this is not where the story ends as 1 week on (i.e. tonight) I tried to start my car up at work and got the same 'Loose Connection' message and the car refuses to start!

I'm going to take it back to the garage for them to look at and hopefully they will find the root of the problem. I'll make sure they check the connections mentioned by deckchair5 and masson (cheers guys).

With this new info does this shed any light on anything else they should be looking at?

Any help would be much appreciated!

Jamie

re: Won't Start & Loose Connection Problem [ECU bad contact]

Ecu

re: Won't Start & Loose Connection Problem [ECU bad contact]

If it is likely to be an ECU problem am I best taking it to a FIAT dealer/specialist?

Can ECU's be 'fixed' or am I looking at a potential new one?!

Cheers,

Jamie

re: Won't Start & Loose Connection Problem [ECU bad contact]

One thing worth checking- towards the back of the battery tray, inner wing side, where the wiring loom exits connector D4 and loops outside, around and underneath, check if the harness has chaffed-through there.

I had a JTD with similar faults to yours (started and ran, but no dials/fuel/coolant levels and 'loose connection' on the display). After much searching I found several main wires had been cut through, including a CAN wire and causing numerous errors.

re: Won't Start & Loose Connection Problem [ECU bad contact]

Just wanted to update on this...

I decided to bite the bullet and take my car to the local main Fiat dealer to have a look at it.

Turns out that the connections coming in/out of the ECU were filthy and the copper connections had actually changed colour!?

Also the mechanic bloke suspected a possible bad ECU earth was also causing issues. Oh and the battery was very low....and the ECU had about a million error messages logged which were checked and cleared off!

So a mixed bag of things going on. I've had no 'loose connection' or any other messages since so fingers crossed all is sorted.

Many thanks to all for your advice.

Jamie

re: Won't Start & Loose Connection Problem [ECU bad contact]

It's good to hear that you've made some headway, and hopefully got it fixed. I do have one question though, out of curiosity more than anything. How much did Fiat sting you for the check?

re: Won't Start & Loose Connection Problem [ECU bad contact]

ChrisMClark said:

It's good to hear that you've made some headway, and hopefully got it fixed. I do have one question though, out of curiosity more than anything. How much did Fiat sting you for the check?

Click to expand...

i was going to ask exactly the same thing

I have a 2.4 Abarth with exactly the same problems , loose connection and ASR failure, it used to start and now won't , it has had a new petrol pump and I have also put in a new OEM crankshaft sensor , I have had a very experienced vehicle electrician on it also . I have checked all the cables and all are fine including ECU pins , I have charged battery and even checked brake switch , any Ideas from you guys would be greatly appreciated before I commit harry carry or lose my hair , such a shame because it is a true delight to drive, by the way it is manual and has skyroof , yours in Hope Paul.


PS I have just had a check round and notice there is a whining noise being emitted from the ECU ! is that normal ?.

Peat said:

As this thread is nearly seven years old it will probably be wise to open a new thread with your specifics!

Click to expand...

Thanks Peat