Technical Abarth Loose Connection Issues

[HSSB]

Thanks Deckchair5,

Before I saw this post, I had just been out & had checked the connection at the brakes anyway = seemed fine.

I also wiped & sprayed electrical cleaner into the D4 *again* (its a horror to get at isn't it?), but no avail Still getting the loose connection error etc.. and Maxiscan still comes up with the same codes. Can't see anything visible that springs out in terms of loose or broken wires, though to be fair you can't see a lot due to the cramped nature of the D4 placement

D4 is looking likely suspect, so I'm going to run through the guides on here about it while I defrost my fingers and think about next step..

I have a feeling its going to be a garage, but there's no way I can get to a Fiat Dealer under my own steam (nearest one is Swansea, c 18 miles), which leave my local one - they've been very good on many things in the past, but they don't open again until Monday

 

[Deckchair5]

Perishing weather isn't it. Hands freeze up in no time. I would thaw out a bit and check out the ABS connector and the relevant ECU connector too

As you get the "lost connection" (better to think of it that way than "loose" which is a bad Italian translation) then at least you'll know straight away if you find the fault

Depends what gear you have but with a simple multimeter you could check for continuity between the relevant
ABS connector pin 40 and the ECU pin 61 (locan)
ABS connector pin 24 and the ECU pin 45 (hican)
and that would eliminate D4

If all connections are good then the ABS unit itself may not be putting out the information but i'd expect other warnings to happen if that were the case


ABS unit connector M50


Here's your ABS connector M50 pinout if you haven't got it. You're after pin 24 and pin 40

 

[HSSB]

Sincerest thanks again Deckchair5!

Just been out & taken off / electrical cleaned again the ABS and ECU connectors in the engine bay (no joy again), and now seen this.

I have a multimeter, pretty bog standard cheap one, but would do the job - being a total newbie when it comes to vehicle electrics what readings should I be looking for in the D4?

Cheers

 

[Deckchair5]

What you're trying to do is the simplest test there is so no worries.
If you can check for continuity (no breaks) from the ABS unit to the ECU then you know the D4 connection is ok.

With all power off and the connectors M50 ABS and ECU connectors disconnected, you're simply looking for a connection in the circuit between the relevant pins. So set your multimeter to resistance and look for damned near zero resistance between the relevant pins from ABS unit to the ECU. See above for the pin numbers


Here's your ECU connector A. Make sure you have connector A! You're after pins 45 and 61

 

[HSSB]

okay, so battery positive off, then split the D4 and connect the multimeter to pins 45 and 61 in ECU connector A - check for resistance.

If there is none, then fault must lie on ABS side - is that right?

Just unfreezing my hands again with a hot cup of coffee, then will be out & giving this a go in about 10 mins

Cheers!

 

[HSSB]

Right, just attempted to do this test..

How on earth do you get at the ECU connector with the pins easily? I just can't get in with the multimeter probes with any kind of accuracy as its just such a tight working space

If I take the fusebox lid off that'll give me some extra room, but not enough.. there's not even enough 'slack' on the wiring into connector A to tilt it slightly upwards, which would be a massive help

I'm also somewhat thrown that the connector only has 3 rows of pins, not 4 as shown in the diagram - I'm sure I've got the D4 as identified in the guide on here, but???

Would I be better getting the whole darn fuse box cover off? Might be a tomorrow job as I think I'm going to call it a day for now - temper is fraying somewhat despite the excellent advice on here - for which I am *truly* grateful!

 

[Davren]

being a total newbie when it comes to vehicle electrics

Be very careful with the multimeter probes. The pins and sockets in the connectors are quite delicate. Wouldn't want you to cause another problem.

Depending on the connector, I sometimes use accupuncture needles for this kind of testing.

Dave

 

[HSSB]

Thanks Dave,

believe me, I was ultra careful, and reason I stopped was partly that I couldn't guarantee connecting to the 2 correct pins gently.

Starting to think I was seeing things, but I swear there were only 3 rows of pins, not 4 - there were definitely only 3 rows of sockets for them to match to on the other half of the connector. Any ideas anyone?

..Also, in Deckchair5's guide the D4 looks to be a lot more accessible than on my car as the leads running from it to the ECU look to be free, whereas mine disappear down and don't seem to have any slack (or are maybe threaded through / attached somewhere out of sight?)

 

[HSSB]

Hang on - just a thought - have I been checking wrong connector? I've been trying to get at the pin connector side of the D4, when actually Deckchair5 you mentioned ECU Connector A - is that a different one e.g. the one off the ABS unit?

Apologies if it is & I have got this totally wrong - did warn you I'm a newb when it comes to electrical stuff!

 

[Davren]

Depends what gear you have but with a simple multimeter you could check for continuity between the relevant
ABS connector pin 40 and the ECU pin 61 (locan)
ABS connector pin 24 and the ECU pin 45 (hican)
and that would eliminate D4

Decks is suggesting you check for continuity between

pin 40 of the ABS connector and pin 61 of the engine management ECU connector.

and also check for continuity between

pin 24 of the ABS connnector and pin 45 of the engine management ECU connector.

Disconnect both connectors before doing the test.

Dave.

 

[Deckchair5]

Yes you'll need to be careful with connector pins of course and a quick read up of my guide here could help you on your way

https://www.fiatforum.com/stilo-guides/109469-electrical-component-testing-made-easy.html



But this is where i would be testing-from ABS ecu to engine ECU
If you have connection between the relevant pins then you wont have to worry about D4

 

[HSSB]

Decks is suggesting you check for continuity between

pin 40 of the ABS connector and pin 61 of the engine management ECU connector.

and also check for continuity between

pin 24 of the ABS connnector and pin 45 of the engine management ECU connector.

Disconnect both connectors before doing the test.

Dave.

Thanks Dave - I understand what I need to do, just unsure I've got the right connector - could just be me being dim (highly likely)

I've been looking at the two sides of the D4 - as shown in pictures in posts 100 and 102 on this thread. These have 3 rows of connectors, and what look like 3 corresponding rows of pins to plug into them.

The post 104 picture shows 4 rows of pins numbered, which makes me think I'm at the wrong place.

Both you & Decks refer to the ABS connector & ECU connector - can you outline for me (in idiot's terms ) exactly where I should expect to find this?

Truly grateful for the help I'm getting, but I'm genuinely all at sea here - my [previous problem & this one are the only times I've delved into the car electrics.

 

[Deckchair5]

First job
Sit down and have a cup of tea

Post 102 shows the ABS unit ecu M50
Post 104 shows the engine ecu M10 connector A (there are two)


Abarth engine ECU M10


ABS unit ecu M50

This is pretty advanced stuff though so if you feel out of your depth then leave it as the possibility of doing harm if you're heavy handed is quite high

 

[HSSB]

Thanks Decks - I think that means I've looked at incorrect connector I think

So ECU connector (M10) is the one pretty to the right hand side of the engine? Just looking for an engine bay pic so I can point out to ensure I have id'd correct one this time.....

 

[HSSB]

Got it!! Doh - have got the idea now...

Sorry, not normally this dim - put it down to stress and freezing cold Thanks for your patience all, especially as mine with the car was wearing a bit thin!

Starting to lose the light now, so think I'll be extra cautious and make this a first thing in the morning job rather than risk any damage (I'm pretty deft with my hands as I've done a fair bit of PC hardware repair / assembly, which can be tricky & delicate stuff, so confident I can do this correctly with good light). M10A is the one on the left side as you look down on the engine from the front - correct?

If these check out with minimal resistance then that would rule D4 out and points to a problem ABS side then?

 

[Deckchair5]

M10A is the one on the left side as you look down on the engine from the front - correct?
Each Stilo engine size is different so I can't help you there. If they're not marked then look for colour of wire to pin 1 perhaps will give the clue

If there IS continuity between those two connectors then things start to get heavier. Never rule out "Is the connector actually making contact?"

I was hoping movement at the connectors might be enough to make things happen and show where the problem lies. The engine ECU connectors seem very prone to poor contact problems

 

[HSSB]

Good Afternoon, and the happiest of New year's to you all,

Quick update - I've been out there this mornig doing Deck's test, and the result seems to suggest high resistance between the pins (i.e. no connection).

To be 100% honest I think I tested correct pins, but not beyond the bounds of possibility I made an error somewhere... Resistance showing on both.

I also took the opportunity to get both ECU connectors, ABS connector *and* D4 wiped again and treated with electrical contact cleaner.

..still getting loose connection etc.. and same error codes stored in the Maxiscan.

New wrinkle today is that I now also get Parking Sensor Failure flash up & off, accompanied by the fuel guage zeroing simultaneously.

Battery output & earths also checked again, and still couldn't see any obvious issue there either.

Cheers!

 

[Davren]

I also took the opportunity to get both ECU connectors, ABS connector *and* D4 wiped again and treated with electrical contact cleaner.

You say "wiped", you need to disconnect the 2 halves of the D4 connector, then spray inside both halves with electrical contact cleaner.... let it dry for a few minutes and reconnect it. Just doing this will often solve several Stilo electrical problems. Wiping the outside of the connector does nothing.

Dave.

 

[HSSB]

Hi Dave,

Sorry to be unclear - did that, sprayed both sides with contact cleaner and allowed to dry, then also 'wiped' flat surfaces gently inside & out.

I'm thinking the prob lies with voltage and/or D4, but not sure what else to do with it - it has now been disconnected, cleaned, sprayed with contact cleaner, dried 3-4 times in the last couple of days with no result.

If I get no further over the weeked its off to a garage with the car on Monday anyway

Ta!

 

[Deckchair5]

If you have located the correct pins then that would be alarming to have an open circuit there but with no connection on both lines i would suspect you have the wrong pins. I know it's very easy to get the wrong pins and not all wiring diags or wiring colours are correct just to make it interesting