DME - have I broken it?

[glastoveteran]

I'm slightly worried I've properly cocked up here whilst fitting my cruise control, but does anyone happen to know of any close up photos of the pins on the DME? Or know whether one should be shorter than the rest?

I've followed BMW's instructions for wiring the CC into the DME but suspect that I've broken a pin on the DME. In fairness the instructions are wrong and say to use the wrong wire which has resulted in this pin breaking - honest!

[srhutch]

If you have broken one of the pins your dealer can supply a new one that will come attached to approx 6" of wire so can be spliced into the exisitng wire without to much trouble.

[glastoveteran]

Thanks - though I think it's a bit more serious than that! I mean one of the pins on the actual DME connected directly to the circuit board...

If I have broken it, then I can't see any way of repairing it other than opening the DME and getting a new pin soldered on...

[srhutch]

Sh!t did realise you meant that, which pin, the one with the new wire fitted?

[glastoveteran]

Yep - it looks like a very clean break hence wondering whether it was always shorter, but it seems too much of a coincidence. Sh!t indeed!

The CC retrofit kit comes with a couple of different contacts that you crimp to the wire before inserting into the plug, and that plug then connects with the pins on the DME. Whether there is something non-standard about my car I don't know, but the instructions definitely say to crimp the wrong contact on.

I guess I've got three options:

1) The pin wasn't in use before, so I could just undo my hard work, take the cruise out and forget I ever tried.
2) Try and get BMW to sort the problem seeing as the instructions do appear to be wrong.
3) Try and get the DME repaired somewhere - after all it's only just reattaching a new pin.

It's one of those things that I knew I should be attempting myself, but everything else went so smoothly and this happening really was bad luck!

[cj10jeeper]

Sounds like a real bit of bad luck if you've broken a pin off. Frankly I'll give you a 100:1 they should all be the same size, but equally pins don't usually break half way down,tending to be at the base or usually bend. It could be a blank to ensure correct insertion of the plug?

So if you have it connected up is everything working or not? That to me is the decided as it may be an unused pin. Pointless worrying if all works.

If not find out the wire colour that corresponds from the plug and it can be looked up where it goes and what connected to

[glastoveteran]

Well, engine seems fine and no warning lights so that's all good, but the cruise control that I've fitted isn't working.

The pin in question previously had nothing connected to it on the socket, but it's the one that I've now connected the cruise control to. So if I have broken it then the worse case is that the CC that I've just installed will never work.

I think the pin that's broken (assuming it has broken) is now too short to make contact with the new connection that I've added to the plug.

What has been an otherwise smooth cruise control install has clearly gone about as wrong as it can go!

Reckon someone could remove the DME casing and connect a new pin to the circuit board easily enough?

[cj10jeeper]

OK - so it looks like you put the new female connector in wrong or out of alignment and in reconnecting it the pin broke off.

Good news is that as you say only the newly wired cc will not work so you have time to thin and not a car off road situation.

Can the unit be opened and a new pin fitted? Well I'm sure a skilled person witht he right kit could do it, but I have my doubts that an amateur could do the job, given the way these things are assembled internally, how close the pins are etc.

Best start pricing a new unit up first to see if it's the easiest route

[peartreeproductions]

Hi Glasto,

Really sorry to hear your bad luck. Having just done this myself I can make you feel a 'little' better insofar as the instructions are hopeless on the N52 engine range. They do provide two types of pin to be connected and having seen them i can imagine that the wrong one would indeed break a pin in the DME. Having had the DME out a few times lately I cannot remember any short pins on it.

I havent had a chance to check my DME but the dealer did tell me that the existing wire was removed and the CC wire (blue?) replaced it. So my gut instinct would be if you have broken the pin the car should be fine without it though you will later have an issue with the CC retrofit.

I would guess a good electronics engineer should be able to solder a new pin on for a price?

[srhutch]

peartree, from what you say one wire was removed and replaced with the CC wire, this doenst seem to be glasto has done as he has put the wire in a spare docket (unless I have read the posts wrong.

Glasto also mentions the instructions are wrong, so perhaps all is not lost.

Just looking thorught the PDF instruction I have it says to connect the blue wire to pin4 where as on your other post it appears you have connected to pin6 (or is this where the instructions are wrong).

[glastoveteran]

Thanks all. FWIW here's where the confusion lies in the instructions (in case it helps anyone). The main wire to the DME on the supplied harness is blue with a black stripe. This already has a socket contact on the end. Also supplied in the kit are two short (6") wires with socket contacts on the end. One of these is solid blue and one solid black. The socket contact on the black one is identical to the socket contact already on the harness.

The instructions for the N52 engine tell you to cut off the socket contact on the harness and connect the black one, which is identical. Obviously seeing no point in cutting one contact off to replace it with exactly the same contact I just used the one already attached to the harness. It seems that both this contact, and the black one they tell you to use, are wrong, and is why the pin has broken on the DME. The correct socket contact is the solid blue one, which I have now connected but it won't make contact with the pin.

Supplied instructions here: http://89.200.137.251/CruiseControlRetrofit.pdf

Steve are you looking at the N46 instructions when you say pin 4? On the N52 it says pin 39 which is what I've done in these photos:





You can tell by the fact that it looks different to the rest that it's the wrong contact, but didn't know this before connecting the plug.

To make things more confusing there is no natural 42 pin plug as stated in the instructions either, just a black 44 pin. Maybe that is also wrong, and I shoould in fact be connecting it elsewhere, which means that broken pin doesn't matter...

Not really sure where I stand with BMW if their instructions are wrong as I am the one that's actually broken it, but that's my first port of call this morning. Not really sure whether to take it to the dealer or not as they may just charge me a diagnosis fee to tell me that I've broken that pin....

Oh and it's about £1k for a new DME so won't be going down that route!

[srhutch]

Different instruction to the ones I found on here

http://thegannet.bulldoghome.com/pages/ ... oghome_com

The instructions you have state N52 built after 09/06, my car was built 08/06 but guess those instructions sill are OK

[glastoveteran]

Very interesting...

The dates on the two documents are October 2006 and April 2009 so they have obviously revised them.

Do you know when they introduced the N52 engine?

I'm confused - maybe I should follow the N52 instructions from that older document... I do at least have the black 26 pin plug described in the older doc, whereas I don't have the natural 42 pin described in the newer doc...

Are you going to have a stab at this at some point Steve?

[jamiez]

glastoveteran - did you get this resolved either way?

Im at the point of feeding the blue wire into the engine bay and then connecting it into the DME socket, but i have 3 questions

1) Do i need to take the panel off below the glovebox in order to see a "hole" to supply the blue wire into the engine bay - near the DME unit?
2) The socket in this pic - which bit does it actually unclip from? Is the DME the unit laying on its side and you first have to take the blackish cover off the top via the clips and then slide this out?

3) So from your post on here, i understand i need to connect the SOLID BLUE 6 inch wire to the blue/black wire from the harness and then allow that to connect into the DME. BUT which pin on the DME do i use? It appears to be 39 according to one set (newer) instructions but pin 26 on another set...


...


Hummmm

Jamie

[peartreeproductions]

Hi Jamie,

in reply to your questions;

1) yes
2)the DME unit is the black box laying on its side inside a container in front of the glovebox, inside the engine compartment (rubbish description). You will need to unplug the relevant plug and release it.
3) As far as the pin you chose well thats where the instructions ran out of ideas for me and glasto IIRC. I bottled it and went to BMW to complete the job. If you want me to have a look to see where they plugged it in I can let you know.

I have a 2006 2.5si (same engine code, different poke!)