C5 electrical issues (poss bcm?)

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rob78
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Re: C5 electrical issues (poss bcm?)

Post by rob78 »

either way i hope ive not bought a turd

ba dum dum tsssssssh #-o
rob78
Posts: 57
Joined: 24 Jan 2016, 18:26

Re: C5 electrical issues (poss bcm?)

Post by rob78 »

right

recieved all the parts but the ecu is wrong the connectors are different

but..........

THE DOORS HAVE UNLOCKED !

- downside is the car wont start lol

so I put the old bcm back in and.........

THE DOORS LOCKED AGAIN !

- upside is the car starts.......I think this has isolated the fault though nice to know I was thinking in this direction
rob78
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Re: C5 electrical issues (poss bcm?)

Post by rob78 »

morning folks

Ive hit a bit of snag with the BCM transplant, Having got the new BCM fitted I got the 4 digit unlock code and then configured it via lexia using the rpo number so all good up until that point I think & its matched with the ecu according to the interface. I only used the supplied replacememnt BCM as the ECU was the wrong type. I have not installed the immobiliser ring nor have I used the key that came with the BCM & the ECU as the shape is different.

problem now is it will not reprogram the key either via lexia or manually. It just says reprogramming failed.

I have no power to the electric windows either at this point so Im not sure if I can reset the BCM as I cannot open the drivers door to insert the key etc at the required points, im assuming this step is required so I dont know where to go from here, except maybe fitting the old BCM again, using that to lower the windows, then whilst the window is down go back to the new BCM and then try and reset it hoping that the windows dont go up automatically.

Any help would be appreciated as I really feel ive made progress with the help you guys have given me and I dont want to admit defeat just yet :-D
Stempy
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Re: C5 electrical issues (poss bcm?)

Post by Stempy »

I don't think you will be able to programme it unless you have it virginised.
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GiveMeABreak
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Re: C5 electrical issues (poss bcm?)

Post by GiveMeABreak »

I'm not sure I fully understand where you're at, but surely you will need the new transponder fitted and use the new key to start it as these have to be matched and you say you already have your original ECU working with the new BSI? I'm not sure but to actually start the car I think you will need to have the correct engine ECU too! If that's the wrong one then can't you send them back and get another set now that you know the one you need with right connectors ?
rob78
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Re: C5 electrical issues (poss bcm?)

Post by rob78 »

ok ive fitted the replacement bcm to the existing wiring, the ecu recognises it in lexia and lexia can communicate with it fine

I got the 4 digit code to enable me to access the replacement bcm via lexia, so i have set that up manually via the settings lexia knows are right for my car which it acertains from the VIN number (i think)

I have just fitted the old bcm back in, lowered the drivers window then put the replacement bcm back in, I will now try the bcm reset procedure that you posted earlier.

with the old bcm in, the car starts fine (so it is matched to the old key)

with the replacement bcm fitted the car does not start (must be because it doesnt recognise the key)

I have a key that was sent with the replacement bcm, along with its transponder ring (which does not fit my barrel so that key is pretty useless)

would it recognise the key if I was to move the transponder chip from the replacement key to the key that belongs to the car along with the transponder ring or am I now in a situation where I need to virginise the bcm and get a new key?

hope thats a clearer explanation! Ive ordered another bcm & ecu (that will fit) just incase!
Hell Razor5543
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Re: C5 electrical issues (poss bcm?)

Post by Hell Razor5543 »

Before you decide taking the key apart (to transfer bits across) get hold of an identical style key from your local scrappy. This is to practise on. You don't want to kill a working key! Most scrappys will (unless they have an order for keys, locks, barrels and so on) bin the keys. I got one (I needed a replacement membrane, but could not get the right one from e-bay, and the dealers only wanted to sell a complete key) for £5.
rob78
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Re: C5 electrical issues (poss bcm?)

Post by rob78 »

thanks for that james but it made no difference, ive put the old module back in and the car and the original key back together and we're no worse off than we were before, bcm module reset, back doors locked as soon as they shut but car starts and runs fine.

Ive ordered another set of bcm / ecu / key this one has the right connectors on it and ive boxed up the replacement one to send off.

Im only £18 quid down which is what it cost me for the bcm unlock PIN so i can cope with that #-o
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GiveMeABreak
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Re: C5 electrical issues (poss bcm?)

Post by GiveMeABreak »

Sounds like a safe bet Rob. Better to fit a complete working set and reduce future issues! At least you'll be in the know when it comes to someone else having this issue!
rob78
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Re: C5 electrical issues (poss bcm?)

Post by rob78 »

indeed I will Marc should be able to save someone else the grief lol
rob78
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Re: C5 electrical issues (poss bcm?)

Post by rob78 »

Well.....

finally cracked it!

swopped the bcm, ecu, transponder ring and key surround (not the fob but actually the plastic bit the blade locates into) and we have a winner. Car starts and the doors all work so does the central locking.

car seems a little sluggish but im guessing the ecu needs to learn its parameters maybe and sort itself out only been out for a short drive its only £40 for a custom remap file off a guy I use but I think I will wait and get it mot'd before I fork out more money for that though.

Ended up paying £45 for the parts but all the electrics work as they should only downside is the stereo is beeping at me but im thinking thats because of the stuff I have changed, oh and the clock now showing around 200k miles rather than 145k lol.

thanks for all your suggestions and advice finally got there in the end :-D
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GiveMeABreak
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Re: C5 electrical issues (poss bcm?)

Post by GiveMeABreak »

Good news Rob, it's always a relief when you turn the key and it all works! The BSI will just need to be told the correct type of audio system in your car as it still thinks it is connected to the unit from the donor vehicle. Don't forget to check the correct multi screen option too and any hands free unit, as it is now apparent the donor car had a different system.
rob78
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Re: C5 electrical issues (poss bcm?)

Post by rob78 »

ahh right so i dont have to go out and get a stereo without a code then ? one of the bcm sets i bought and then returned came with a stereo which i thought was because it was coded to that ecu I didnt realise there was an option to change it on lexia.

***** just found the option in lexia to enter the VIN of the ecu/bcm donor on the radio menu and the beeping has stopped :) *****

Is it worth getting the PIN for the new bcm and setting it up with the correct VIN code or am I just going to cause myself problems and its best to leave it alone now its running?
rob78
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Re: C5 electrical issues (poss bcm?)

Post by rob78 »

MOT at 10am tomorrow [-o<

checked it over and all i found amiss was the fuel latch that i levered off (drilled the clips that hold the liner in the wheel arch as they were goosed, refitted the latch, tapped the clips out and fitted new bolts and washers and one wheel stud was missing which i duly rescued from my local scrappy.

I checked the fluids and spotted the suspension reservoir was empty for some reason (im crossing my fingers its not all leaking out under the car) so i refilled it with the lds fluid (following the haynes manual i might add, so i lowered the car first and then filled to halfway) and it seems to ride better im just crossing my fingers as I looked at the receipt from the last service and it has a note that the rear dampners are weeping as well as the osf one, I had a look and couldnt see anything but gave them a good cleaning off so will have to suck it and see.
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GiveMeABreak
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Re: C5 electrical issues (poss bcm?)

Post by GiveMeABreak »

Good luck with the MOT - they may have an advisory recorded for leaks on the last MOT, but fingers crossed they don't home in on it specifically. If you are loosing fluid you do need to find it though...