Technical Safety Features disabled

[victimist]

Hi Guys

The wife has a 500, 14 plate. The other night she went on a small round trip (4 miles) and when she got home she told me she had lights come up on the dash. She's adamant the lights came on for no apparent reason. The car seems to drive like normal even though all the lights are on.

The symptoms are:
* Main Airbag light on
* Passenger Airbag light on
* Seatbelt Light on
* General Fault Light on (Yellow triangle with exclamation)
* Odometer displays, "Fuel cut-out unavailable"
* Millage is flashing


Things I have tried so far:
* Read for fault codes with Mobile app “Torque” – None stored
* Checked cables under the seats – Nothing obviously disconnected.
* Indicator trick, (right, left, right, left) to try override the fuel cut-out – No affect at all.
* Service reset (accelerator pedal down 3 times)
* Disconnected Battery for an hour – No affect
* Looked for Airbag Relays in the fuse box, but couldn’t find any.
* Called the dealer who advised its £90 for a diagnostic and couldn’t offer any help otherwise.

I came across some posts which explain that flashing millage is an indication proxy alignment is required. From this I suspect some sort of safety module must have crapped out (potentially the airbag). I researched the proxi alignment procedure. As luck were to have it, I have MultiECUScan2.2 through issues with electric steering on the wife’s previous punto.

So I connected the car up to MultiECUScan and 1st checked what I could connect to. Engine, ABS fine but I was unable to connect to airbags. This makes sense and also ties in with the theory of “proxy alignment” being required – On the airbag module perhaps?.

I proceeded to try run the proxy alignment, but if fails with “Unreliable communication detected”. This is 100% the elm interface I’m trying to use. So, the investigation took a new turn.

I came across posts where guys reported removing a resistor sorts the issue. Unfortunately, my Elm tool is not the same board and of different shape. I’m also not convinced that buying the latest version of MultiECUScan will fix the communication issue. And with the amount of fake Chinese Elms on eBay, I feel it would be a lottery as to whether or not ill find a working one.

So ..... For now I’m stuck, but decided to come on here to ask if anyone knows anything I could try, or whether anyone is able to help me fix this?

As a last resort, im going to jump the car with mine, to see if its potentially a weak battery issue, but i feel im clutching at straws

Appreciate any help you guys can afford to offer.
Thanks!!

 

[306maxi]

First thought would be that it’s a weak battery.

 

[victimist]

Thanks 306maxi. Just jumped it off mine, no difference; All symptoms remained. Least a weak battery is ruled out now

 

[chris3234]

Two other things can be worth a try checking and cleaning the main earth cables
And checking the wiring the the rear boot/hatch as the cables can break

 

[jrkitching]

All these warning messages are typically what you see with the all too common hatch wiring fault issue. When your wife went out last night, did she open the rear hatch?

Before you do anything else, disconnect the battery and carefully check the integrity of the wiring where it enters the hatchback; you will have to pull back the grommets, and may have to strip some of the wrapping around the loom. The cables inside usually break before there's any sign of distress in the outer insulation wrap or rubber sleeve.

It's pointless trying to run diagnostics on a car if there's a hardware fault, and trying to do so could actually cause further damage, so this needs to be ruled out before you do anything else.

Hatch wiring faults have been known to fry the airbag ECU, but usually only a reset is needed once the wiring is repaired. The fuel cutoff warning is the giveaway, as the fuel cutoff in the 500 is implemented via the airbag ECU.

 

[victimist]

Cheers Chris & JR.

When I disconnected the battery previously, I cleaned the terminals and made sure the connections were good.

Appreciate the information about the hatch wiring. Would never have thought to look there. Found a good example of some bad wiring (https://www.fiatforum.com/gallery/data/500/image2609.jpg) before I went to look at the wife's car. ** She confirmed she hadn't used the boot before the issue occurred. **

Upon inspection of the hatch loom, the rubber grommets were in good shape. 1st checked the hatch side, pulled back the rubber but the wires look pretty much new and no visible damage. Same on the chassis side. (admittingly, I didn't pull off any insulation wrapping)

I then pulled the plastic trim from the column inside the car where the loom was leading to, but didn't see any damage to wiring under there either. As before, it all looked new.

Think I may have also found a compatible diagnostic tool to perform proxi alignment. https://www.gendan.co.uk/product_FESCAN.html

 

[typecastboy]

Definitely a battery fault. Get a new stop start one.

 

[victimist]

Definitely a battery fault. Get a new stop start one.

I have an Astra and used it to jump the 500 - but it made no difference?

 

[typecastboy]

I have an Astra and used it to jump the 500 - but it made no difference?

But it’s still running off of what is probably a duff battery. Enough power to start it but the computers are very sensitive to the correct amps. I’ve had similar several times and every time a new battery has fixed it.

 

[Texas149]

+1 on a iffy battery sending you on a wild goose chase fault finding!
My daughters ( new to her ) 08 1.2 lounge was throwing a "Have Power Steering Checked" EML and I was planning all sorts of remedies but upon starting with the cheapest ( £42 for a Duracell non SS battery) the 'fault' never reared again!
Paul m.

 

[victimist]

OK - I stuck my battery in. Mine being 600A 60Ah 12V, and hers 450A 63Ah 12V. Sadly no difference.

I poked around and found the Airbag ECU at the bottom of the centre console (at the back). Checked the cables there too. Again nothing obviously wrong with them. :bang:

 

[jrkitching]

OK - I stuck my battery in. Mine being 600A 60Ah 12V, and hers 450A 63Ah 12V. Sadly no difference.

I poked around and found the Airbag ECU at the bottom of the centre console (at the back). Checked the cables there too. Again nothing obviously wrong with them. :bang:

We have had a few reports here of random airbag ECU failure. A new one from a main dealer won't be cheap, but you could get a secondhand one for much less money.

@typecastboy can tell you all about where to get one and what reprogramming may need to be done.

Remember though that the airbag ECU is an essential part of the car's crash protection system; if yours is now faulty, the only way to give yourself the best possible reassurance that it will work as intended is to have a new ECU fitted and programmed by a franchised dealer or airbag specialist. Fitting a secondhand unit of unknown provenance will likely work 99.9% of the time, but the other 0.1% just might be the difference between life and death for someone.

 

[typecastboy]

Can we go back to multi ecu scan?

So you couldn’t connect to the ECU but you could to the engine one? To connect o the airbag ecu you need the yellow adapter on your ELM cable, to connect to the engine you don’t use any adapter. Could that be why you can’t connect?

I have a contact via eBay that I have used to reset and fix ECUs. He charges £30 via post. Another member on this forum contacted me with an ECU problem and he got his reset but still had problem with an airbag. He drove down to me a couple of weeks ago and we found the problem. If there is a problem with your ECU then I would expect MES to find it. For the sake of £30 I would send it off and get it reset or you can buy one on eBay just make sure it’s the same model number. Prices vary but you will get one for under £100.

 

[victimist]

Thanks for the continued support guys!!

Yes I hear what you say about the safety, and am in agreement jrkitching. Luckily she only drives in our local town … Also give me a bit of time to get this sorted. MOT is due next June.
typecastboy I don't have the yellow adaptor for MES - so purchased it yesterday. Just waiting for it to arrive now. (Hopefully this is why I am currently unable to communicate with the Airbag ECU). Once the yellow adaptor arrives, I plan to see if it has any faults registered on the Airbag ECU, reset it if possible, and that's if it even communicates I guess. The yellow adaptor is the key I'm missing though.

As the odometer is flashing, could that be a clue that it just requires Proxi alignment??

Should I find I am still unable to see the Airbag ECU on the CAN, then ill go down the ebay route.

I'm an IT consultant by trade so doing this type of thing is something I'm luckily familiar with. And if in the end, I need to admit defeat and take it into a dealer... then at least Ill have knowledge so they wont be able to baffle me.

 

[typecastboy]

The forum member i mentioned that drove down from Cambridge to me recently had flashing mileage but couldn’t do a proxy alignment because of an airbag light. Once we sorted the airbag problem by finding which bag and temporarily putting a resistor in the plug we didn’t need to do a proxy alignment, the mileage just stopped flashing once I had erased all his error codes. Yours will most likely be the same. It will tell you whether it needs a proxy or not. It probably won’t as it’s not a module out of another car. Your car has just lost connectivity somehow at some point which has made the mileage flash. I’m quietly confident that MES will sort it for you.

 

[victimist]

The forum member i mentioned that drove down from Cambridge to me recently had flashing mileage but couldn’t do a proxy alignment because of an airbag light. Once we sorted the airbag problem by finding which bag and temporarily putting a resistor in the plug we didn’t need to do a proxy alignment, the mileage just stopped flashing once I had erased all his error codes. Yours will most likely be the same. It will tell you whether it needs a proxy or not. It probably won’t as it’s not a module out of another car. Your car has just lost connectivity somehow at some point which has made the mileage flash. I’m quietly confident that MES will sort it for you.

Cheers for the info and vote of confidence typecastboy

Will keep you guys posted once I have the yellow adaptor to hand

 

[victimist]

Evening All

So the yellow adaptor arrived today - Exciting Times!

I ran a DTC Scan (with the yellow adaptor) and the following errors were reported ...

Body Computer
B10AA-4A - PROXI configuration control
U1726-87 - Airbag Node (NAB)

Dashboard / IPC (Instrument Panel Cluster)
U1726-87 - No Communication with Airbag control unit


Again without the yellow adaptor ...

Engine / ECM
U0331-81 - Communication with Body Computer (BCM/NBC)

Body / BCM (Body Computer Module)
B10AA-4A - PROXI configuration control
U1726-87 - Airbag Node (NAB)


It's clearly not communicating with the Airbag Control Unit. So, I figured I'll try the CAN Setup / PROXI Alignment Procedure, thinking it may just need recoupling to the CAN. When I entered into the PROXI Alignment Menu, in Red it had Airbag Node (NAB/ORC) with a status of "Removed".

I proceeded to reset all the codes and turned the ignition off. When I turned it on and rescanned, all the faults had came back.

That pretty much concluded my ability to resolve the issue with a laptop (for now). Simply cannot couple something that doesn't exist. It seems the Airbag controller unit has completely failed for no reason. My next mission is to hunt for a replacement.

The Airbag Unit itself is a Sensore AIRBAG 12V, D220, OEM Number: 51918659

Out of interest, is there anything I should be aware of, or lookout for before purchasing a replacement? If anyone could perhaps recommend a trustworthy source to acquire one from at a reasonable price that would be very useful.

Thanks for your help folks!

 

[victimist]

Hi. Bit more info on the controller. I have discovered an easy test is to disconnect the Airbag unit. With a multimeter, test pin 1 (earth) and 2 (live) off the loom. You should get a ignition reading when the ignition is on. If you get power, the fault points at the Airbag Unit itself having failed. This is true in my case. Thought id share the knowledge Still on the hunt for a replacement unit.

 

[typecastboy]

Hi. Bit more info on the controller. I have discovered an easy test is to disconnect the Airbag unit. With a multimeter, test pin 1 (earth) and 2 (live) off the loom. You should get a ignition reading when the ignition is on. If you get power, the fault points at the Airbag Unit itself having failed. This is true in my case. Thought id share the knowledge Still on the hunt for a replacement unit.

Which loom? There are two separate plugs.

 

[typecastboy]

I always buy replacement ones on eBay. They vary in price but you should get one for under £100.