Technical MultiECUScan

[BIGBAND39]

Hello Everyone!

I'm new to the group after purchasing a 2012 Fiat 500 Sport that needs some help. One of the issues the car faces is the typical rear hatch loom wiring. I've purchased a repair kit (which apparently only come from Latvia) but I wanted to see if I could connect to the airbag ECU the way it sits now. I intended on purchasing MultiECUScan and followed the website's information at the top of the page directing buyers to purchase OBDLink MX+. After some further research, I found that this won't connect as is. Can anyone tell me exactly what I would have to purchase and the best place to get it from? Would a setup like this work?

KKL 4 Adapters Engine Airbag ABS Fits Fiat Alfa Diagnostic for MultiECUScan | eBay

If a CAN connection is required you will need an ELM unit also, (for use with yellow adaptor). All 4 coloured cables.

www.ebay.com

Any information would be appreciated!

 

[Baglady1990]

Hi & welcome!
This is what you need https://www.ebay.co.uk/itm/Fits-Fia...=p2349624.m2548.l6249&mkrid=710-127635-2958-0
I bought one & also one off the multiecuscan registered seller list & both work fine

As for the hatch wiring I would suggest (if not already told) don’t drive the car until it’s replaced or you could end up with some serious bills!

 

[BIGBAND39]

Thanks for the tip! My dashboard is already all lit up so the damage may already have been done. Air bag, seat belt, and a deactivated fuel cut off message. Has anyone ever had luck resetting everything after new hatch wiring has been spliced in and everything is fine or am I likely doomed to replace the airbag ECU?

 

[Baglady1990]

@typecastboy is very familiar with this he will update you soon! Has the car had any sort of crash damage?

 

[BIGBAND39]

No accidents but someone did a job with electrical tape and what we in the northeastern part of the states call “swamp Yankee engineering”. The connector for the plate lamp was corroded off so they patched in a replacement lamp as well leading to even more cutting and splicing. That is another message I’m getting. The insulation on some of the wires I can see going from the hatch to the body is damaged and the copper is showing through as well. The rubber wire loom boot is completely missing. I can send a photo of the damaged wires and under the hatch panel if that helps.

 

[chris3234]

No accidents but someone did a job with electrical tape and what we in the northeastern part of the states call “swamp Yankee engineering”. The connector for the plate lamp was corroded off so they patched in a replacement lamp as well leading to even more cutting and splicing. That is another message I’m getting. The insulation on some of the wires I can see going from the hatch to the body is damaged and the copper is showing through as well. The rubber wire loom boot is completely missing. I can send a photo of the damaged wires and under the hatch panel if that helps.

I'd be getting that wiring replaced asap before it does any more damage any bare wiring risks a short

 

[Baglady1990]

As Chris said the wiring needs replacing ASAP I’d be leaving the battery off until it’s completed
Once all wiring sorted then it’s time for MES that will then diagnose any issues hopefully you can clear any codes that are intermittent any present codes in red will need to be addressed

 

[typecastboy]

I've repaired/replaced two or three times. If the wiring is the cause of your Christmas tree display on the dash then the fixing of it will make most, if not all of them just go out. Only resets for blown airbags/seatbelts/pre tensioners etc will require a reset to actually make the lights go out. The codes will still be stored and will show in diagnosticss (MES) as "intermittent". I would certainly recommend getting MES and a set of cables from eBay. You only actually need the yellow one for most of the ECUs except the engine and steering which uses the ELM on its own without a coloured adapter. When you buy the ELM make sure you get a "modified" one.

I think, fix the wiring and see what you're left with. Once you have MES you can connect to the Airbag ECU and see if it's faulty or not.

Don't forget to discconnect the earth terminal of the battery before you start messing with it.

 

[A3jeroen]

There are some pics in my Topolino Grigio topic.
Ifound that the new silicone cables work pretty good. Make sure you have a good crimpingtool. And a second set of hands makes life easier. I put the excess in on both sides after connecting all wires one by one on both sides. I had some wires in the sam colour, so had to measure resistance and put some tape on both sides to not cross them accidentally.

gr J

 

[Baglady1990]

The cover is a lot softer too silicone I believe like the new wires so a lot better!
I did my wires individually one by one took ages hope I never have to do that again!

 

[BIGBAND39]

I actually bought the modified ELM unit that Baglady suggested in her link. It's on its way to the US now from Bridgend, UK and should be here for the end of the month. The wire loom repair kit should be coming shortly after. I've had the battery unplugged in the car now for the last few weeks. When I bought it, the car was so disgusting that I had to remove the seats to fully clean and remove stains from the floors so I disconnected it first. It still needs lower ball joints, struts, shocks, and a valve cover gasket. I can take care of cosmetics and physical repairs and leave it disconnected for now. It's a spare car for family and a gas savings compared to my Chevrolet pickup. I paid $2000 for it (roughly £1400). I know that seems like a lot for one of these in the UK but stateside, the retail on this car with crazy inflation is about $6000. Private party, cars are selling for about $4500. If I can get out of the electrical issues with a $50 repair, I'll be happy to drive around in my little gas miser and enjoy what really is a niche vehicle here. @A3jeroen You mentioned testing resistance. Are the gauge of all the wires in the repair loom the same? Is there anything wrong with cutting and splicing them one by one?

 

[A3jeroen]

No there are IIRC tthree gauges of wire. Two for the heated rear window. Four for other stuff with thicker wire in the loom and a bunch of very thin wires for the rest. But not all of them have exact the same colour as the wiring in the car. And I had two sets of black in the same gauge and two sets pf grey. To prevent crosswiring you have to make sure that you connect the exact same wire.
So I set my multimeter to rresistance to check continuity.
It's easier than it sounds!

gr J