Technical Abarth Loose Connection Issues

[Deckchair5]

re: Abarth - Earth Lead? [AND coil pack]

Wow, that'll be great if that's the end of that problem.
Coil insulation breaking down could result in spark going to easiest source ie arcing to the engine rather than jump across spark gap

I'd check all your spark gaps if you're in any doubt as to how long it's been since you last looked as a too big a gap puts big electrical loads on the coil and, because they then overheat, thermal loads too and breaks down the insulation. The power required to jump the gap increases enormously with a too big gap or worn plug.

Coils just expire too though when they've had enough-poor things

 

[HSSB]

re: Abarth - Earth Lead? [AND coil pack]

Well, 100 miles up today, and still going strong, so I think I'm going to call the problem busted (and keep my fingers crossed). Will probably do a couple of final voltage checks just to be 100% though...

Decks, funnily enough I recently replaced spark plugs - a week or so before the front spring went, which was *just* before this happened.

They were supposed to have been changed when i bought the car a little less than 12 months ago, but the ones that came out were possibly original - truly knackered . From what you say, there's probably been a long term strain on the coil because of this. I've now replaced 3 coils over the time I've ha the car, and I'm seriously thinking of doing the remaining 2 *now* as a precautionary measure.

Anyway, fingers crossed its happy motoring for me now (until next time something beeps..)

 

[Ralph2]

re: Abarth - Earth Lead? [AND coil pack]

I've just spent a 1/2 hour reading this thread in the same way my wife might sit and read a novel. What a tale of mystery and suspense, and the good guy wins in the end. Thanks all! (Nice to see someone knows how the difference between 'lose' and 'loose' as well)

 

[HSSB]

Back again after a long time away. Looking for any ideas on a problem

Got trailered home on Saturday with following symptoms:

Car was running fine (other than a lonstanding problem with the passenger side OCS intermittently giving the airbag fault, which I know I have to get fixed) - was over 100 miles in on a planned 167 mile journey. Stop at services for 'comfort break'.

When I come out, car starts but flashes up Loose Connection error message, swiftly followed by Engine Management System Fail, ASR/ABS and Auto Gearbox failures, ending with the dreaded 'Return to Dealer'

Car runs absolutely fine throughout all this (no missing or anything), but will only select 1st, 2nd and reverse gears, so undriveable - hence trailer home.

i know loose connection is usually voltage drop related, so have checked following:

Engine earth - checks out fine, have an additional earth on there after my last problem anyway

Battery - again, checks out fine, voltages as I would expect when running, and under load (with lights, rear screen heat etc.. all on).

D4 - again, checked & unplugged / replugged. No immediately obvious fault or moisture.

..still comes up with Loose Connection moment I turn the ignition on, though the engine starts & runs fine (albeit in Limp mode).

Is there anything else 'obvious' I should check before consigning the car to one of my local garages, none of whom I really trust, but at least gotta be better than my local Fiat dealers who are truly awful

Many thanks in advance - you guys were brilliant in helping last time, so hoping its 2nd time lucky!

Cheers

Edit to add - just checked out for the brake light issue (with them sticking on causing ASR ABS faults) and it isn't that.

 

[12[X]]

obvious? yes.. what are the error codes? could be a clutch sensor (or is it a flywheel sensor? not to good with auto boxes as i aint got one.. it may just need to be retrained) you say limp mode.. is the engine behaving differently an won't rev/work as it did or is it just the box? Ps.. from my experience a none complete break light switch failure cannot be detected in any way (apart by changing the switch)

 

[HSSB]

Hi 12 [X],

Sorry, not got a fault code reader, so can't give any more detail on that one.

Limp mode = engine runs totally fine, revs cleanly etc.. BUT will selespeed box will only select 1st, 2nd and reverse. I suspect thats due to the apparent auto box fail light that I think is actually due to the Loose Connection message taking all the various systems down rather than the box itself / a sensor in there.

And the brake switch thing - loads of posts on this site about it, but basically they *can* stick on due to a switch by the brake pedal... causes ABS / ESP faults.. Very common problem apparently, but one I've checked out - ii.e checked, and they are not sticking on.

I have a real feeling all the faults are down to the loose connection error, and its a voltage drop issue I'm looking at here.

I'm beginning to wonder of swapping the battery out might help - anyone know if a battery *could* not be giving enough output even if the voltages test out as being okay (i.e. well within the readings that were mentioned when I last had a problem - see previous posts)?

Ta!

 

[Argonought]

Just merged for you as might be some clues within the older issues :chin:

'Loose Connection' certainly translates to weak battery on my JTD (although the message is the ONLY issue for me) so a new battery might be a reasonable investment.

 

[HSSB]

Thanks Argonaut... just saw the amount of posts in here & panicked - thought I'd @rsed the forum up until I realised you'd merged the threads!

Think I'll try a new battery before anything else, just in case. Will prob go for the diesel models battery as many people on here mention that as being better.

Anyone know of anywhere decent to get a battery currently (could be online if I can get next day delivery) - Halfords look overpriced, and I don't fancy havin to do the 30 mile round trip to my nearest dealer unless I have to..

 

[HSSB]

Just a little update.

Tried replacing battery, but that has no effect (to be honest, was not expecting it too, as all the voltage readings I took were well up) - loose connection message comes up the minute the ignition is turned on, followed by cascade of other fault warnings.

Unable to book into a garage today as the only local one I could get to easily in limp mode, which is also usually the best of the local ones here, is not open again until New Year. I seriously doubt I could get the car to my nearest Fiat Dealer under its own steam so pretty much ruling that option out unless as a last resort

Have ordered a Maxiscan fault code reader which hopefully will turn up tomorrow (and is a good investment anyway).. am hoping if I can get the fault codes off I can get an idea of what the problem is..

Will keep forum posted anyway

Cheers

 

[HSSB]

Update:

Maxiscan reader arrived 10 mins ago (now thats fabulous service!)

2 fault codes showing up..

U1706 - ABS / Engine Communication - possibly my longstanding passenger side SOCS fault?

P1314 - according to a couple of web sites I've seen this translates as "Misfire Rate Catalyst Damage Fault Bank 2" - not sure if thats applicable to Fiat though??

2nd one is wierd as I have no discernable misfire. Anyone reckon it could be a coil pack breaking down again as per previous problem? Alternatively, should I be looking at the D4 again - damp / circuit break?

Any advice / opinions *very* gratefully received!

Cheers

 

[Argonought]

The recorded errors at least seem to match dash display.

I'd concentrate on a "Loose connection" message before engine start as this indicates a voltage problem - and translates to poor or broken connection (also bad earth) or a partial short somewhere.

The fault is likely to be in the area of the ABS circuits which should be on a line which is common to gearbox sensors.

A look at the circuit diagram might provide a clue here :chin:

 

[HSSB]

Thanks Argonought,

Yep, I think its voltage related too, the additional warning messages are just Fiat's way of giving me some additional grey hairs

It's absolutely lashing down with rain here, putting paid to doing any more under bonnet work today, but the minute I get a dry hour or so, I'll get out with the trusty multimeter & work through. Also going to give the D4 another thorough checking over

I am 99% certain it ain't an earthing problem, so I'm thinking the partial short is likely what I'm looking for.

 

[Davren]

Update:

Maxiscan reader arrived 10 mins ago (now thats fabulous service!)

2 fault codes showing up..

U1706 - ABS / Engine Communication - possibly my longstanding passenger side SOCS fault?

P1314 - according to a couple of web sites I've seen this translates as "Misfire Rate Catalyst Damage Fault Bank 2" - not sure if thats applicable to Fiat though??

2nd one is wierd as I have no discernable misfire. Anyone reckon it could be a coil pack breaking down again as per previous problem? Alternatively, should I be looking at the D4 again - damp / circuit break?

Any advice / opinions *very* gratefully received!

Cheers

You would only have a bank 2 catalyst fault if you had a V engine (V6, V8, v12 etc.)

Where did you get the definitions for the codes from?

All codes starting with 1 are manufacturer specific and different manufacturers have different definitions for the same code.

According to the Fiat manufacturer code list I have, U1706 is "CAN Network NCM - NFR" (Engine Management ECU - ABS Brake ECU) and P1314 is "Vertical Acc." Not a clue what that one means. (Vertical acceleration perhaps Is it a Stilo or a Harrier?)

Dave.

 

[HSSB]

Hello Dave,

Been checking on those codes, as too darn damp here to go digging under the bonnet.

The original place I found them was a combo of US and Spanish sites via a quick google... I was doubtful over the 2nd at the time.

So, if U1706 is Throttle signal (is that the same as CAN NCM-NFR (Engine Management ECU - Brake ECU, which definition I have also seen posted?), then I need to be getting that checked out.

..I also came across your post elsewhere on this forum about P1314 being Vertical Acc, but haven't been able to track any more detail at all on what that might mean... I don't think there's a button anywhere on the dash marked 'LiftOff' or I'd have tried it by now

I'm still hung up on the 'Loose Connection' error though - - that kicks in as soon as the car starts the checks when the ignition is turned on, and I am sure is at the root of everything.

Fingers crossed for some sunshine (or at least lack of rain!) tomorrow so I can get back under the bonnet & trace things

 

[Davren]

Sorry....I looked up P1706 instead of U1706. Have edited my post #93 now.

I don't know anything about the Selespeed gearbox, but, could "Vertical Acc" mean vertical actuator? Is there such a thing to control changes in the Selespeed box?

Dave.

 

[HSSB]

No probs...

ON the Vetical Actuator, I think the selespeed box does have one (coupla posts on alfa forums about such, and I think its the same unit used??) .

Found http://www.kbmsystems.net/obd_fault_codes_ref.htm useful - it denotes 2nd digit as being transmission related, which would support that hypothesis.

Could a voltage drop issue cause a fault there when ignition switched on maybe?

 

[Argonought]

Seeing as the problem first occurred after a long run then I'd suspect temperature/cooling to be the main cause although it's interesting to theorize that the fault had already occurred before you made the stop.

Might be worth removing anything that gets very warm, such as the ECU, and checking the connection plugs/sockets carefully :chin:

 

[Deckchair5]

U1706 - ABS / Engine Communication - possibly my longstanding passenger side SOCS fault?

If you mean the OCS then no, this is something different

U1706 as you've said is ABS / Engine Communication
So that's CAN network (NCM-NFR)

NCM = ECU
NFR = ABS ecu

The ECU needs the car speed (wheel rotation speed) from the ABS unit to know what gears to use and without it then it's stuffed and goes into limp mode. So that's where your problem lies= Lost can line comms between the ECU and ABS

See item 3 here

 

[HSSB]

Argonought, Deckchair5, thats great (thanks also Davren for getting me on right track).

I know where to start looking now.. will prob start with the ABS sensors at the front wheels as the road up was pretty wet before I stopped & had my breakdown (hmm, don't like the way that sounds, but you know what I mean!)...

Will let you know progress tomorrow - hopefully I might be able to report back good news

Cheers & good night all!

 

[Deckchair5]

Bear in mind it is a CAN line fault ie communications inter nodes between the engine ECU and the ABS ecu, (not between the ABS sensors and the ABS unit)


It goes through connector D4. Ho ho!


D4 to engine ECU


From ABS unit to D4


D4 connector pinout. M50 is the ABS unit