Switching mode K+DCAN cable

[Sebastian46]

Hi,
I have one of those K+DCAN USB cables and I am confused about how to switch the modes of it. When I connect it to my E39 530i touring I can only access DME. All other headunits will bring up the error IFH-0009. When I connect pin 7 and 8 I can access all headunits without changing anything else. But there must be a way to make this possible without hardware modification, right? I could not figure out how to realize this. Can someone help?
Thanks

[David Mc]

I have never heard of a switch-mode K+DCAN interface - I assume the reasons being that on DCAN cars one pin is used for a ethernet connection and the other to tha K data line - on K line cars, both pins are connected to K data lines and that creating a switch mode circuit would cost more than the interface is worth. The 2 most sensible options are both hardware-related:-
1. Use an adapter (such as tha one sold by One Stop electronics) which internally bridges pins 7 & 8 or,
2. Mount a small switch on the OBD plug end of your adapter, which can bridge (for K line) or separate (for DCAN) the connection between pins 7 & 8.

[Sebastian46]

Ok that was just an assumption of me.
So you have to physically connect (K-Line) or disconnect (DCAN) pin 7&8?

[David Mc]

Yes, I think connection by soldering is a bad option as it limits the usefulness of the interface, I have an adapter but consider a switch to be a better option.

[Sebastian46]

Is there anything else to do for switching from K-Line to DCAN then disconnecting pin 7&8? Unfortunately I dont have a DCAN model available.

[David Mc]

As soon as you connect the interface to the car and your computer, run DCAN.exe to configure the comms rate. I have only used my K+DCAN interface with DCAN cars.

[Sebastian46]

Is it necessary to do so every time I want to use DCAN or is the interface staying in DCAN mode once I ran DCAN.exe?

[David Mc]

You only need to run it when you are switching between modes. If you run it the first time you connect to a DCAN car, your computer will retain the settings.

[Sebastian46]

How do I switch back to K-Line? Just by connecting the two pins or is further action on the computer required?

[rebel.ranter]

What year is your e39? Earlier e39 had both the OBD port in the cabin and the round 20 pin connector under the hood.

The OBD port only allowed access to limited modules, I think only the DME in fact.

I always switch my K+D CAN adapter between K and D CAN protocols as I need to, depending on the car that I'm connecting to.
I use the DOS version of the DCAN utility. As mentioned if you only use the adapter on the e39, run the utility once and set the adapter to K CAN and leave it at that.

In fact thinking about it I use the same adapter for INPA, DIS and ISID.

With these K{D CAN cables there are two subtle different versions, one with pin 8 enabled, one with it disabled. The one with it disabled is ideal for e90 newer than 03/07 & that era, these leads often come with a black adapter to re-enable the pin 8 (by just tying it to pin 9) so it will also be suitable for e46/e39/e63 etc. The ones with pin 8 active are just older versions of the cable. Worst cast scenario you just need to modify the cable & stuck a switch on it to toggle pin 8 on/off as needed.

Finally there are a lot of rubbish adapter cables out there. Finding a good one can be tricky.

[Sebastian46]

I have a 2003 E39 so there is no OBD1 anymore. How do you switch the modes physically? Do you use such a adapter to connect Pin 7&8?

[legoman67]

The reason that you need to physically modify it is because its not exactly the correct cable for OBD, but for $20 and 20 minutes of your time its by far the best solution for scanning these cars.If you want to scan Dcan as well you can put a little switch on it that allows you to connect and disconnect pins 7 and 8.

Personally I use Gert's Interface for all OBD cars, and have a K+dcan cable for Dcan cars. No modifications required.

- - - Updated - - -

I have a 2003 E39 so there is no OBD1 anymore. How do you switch the modes physically? Do you use such a adapter to connect Pin 7&8?

If you dont plan to use the cable on any cars that have DCAN(2007+) then you can pop open the case and solder a jumper between them. When you do this the DCAN functionality will no longer work though.

[Sebastian46]

Is there production date from or until which I need the bridge between pin 7&8? I'm confused by all the rumours and half knowledge on the internet.

[328 Power 04]

Is there production date from or until which I need the bridge between pin 7&8? I'm confused by all the rumours and half knowledge on the internet.

bmw_interfaces_big.jpg

[freebo86]

Can someone enlighten me on this k-Dcan cable and pints 7&8.

So I had a E46, ordered a cable (blue, this was 5-6 years ago) the cable worked great on my E46, read everything etc.

Recently I got a 08 E83, using ISTA/D and that same cable I can read the car however I can't read the DME.

Did some research turns out its because pins 7&8 are bridged and 07+ cars don't require these two pins to be bridge. Took the cable apart and of course my pins are bridged. So unbridged them, all excited I go out the cable doesn't work at all. The car can't be read at all now.

Am I missing something here or what? Is it not as simple as just unbridging the two pins?

[RocketSurgeon]

Can someone enlighten me on this k-Dcan cable and pints 7&8.

So I had a E46, ordered a cable (blue, this was 5-6 years ago) the cable worked great on my E46, read everything etc.

Recently I got a 08 E83, using ISTA/D and that same cable I can read the car however I can't read the DME.

Did some research turns out its because pins 7&8 are bridged and 07+ cars don't require these two pins to be bridge. Took the cable apart and of course my pins are bridged. So unbridged them, all excited I go out the cable doesn't work at all. The car can't be read at all now.

Am I missing something here or what? Is it not as simple as just unbridging the two pins?

Use this utility to switch modes on your cable between K-line for older models, and D-CAN for newer ones
https://mega.nz/#!1sdxHAzC!uuNqqwRk0...aOg4LnzFhgY0vM

[freebo86]

Thanks RocketSurgeon.

And this works with any cable? I'll go this a shot tonight.

Anything else in particular I need to this like step wise? Plug cable into computer, then do this? Or plug it into car start the diag software then start this D-CAN software?

[RocketSurgeon]

The instructions I have are pretty vague. I assume you have the cable connected to both computer and car, select the correct com port for your cable, and pick the mode. Pretty much all the cables run ATMEGA processor chips, so I'm figuring this utility is pretty universal. Supposedly if you get a cable with the switch built in, it can pick the correct mode automatically, and you don't need this utility.

[328 Power 04]

I don't know about you, but I've never had good luck with that utility, on multiple K+DCAN cables.. or at least never noticed a difference or a need for it.
I tried it for curiosity... but usually at my desk.

However my K+DCAN cables simply worked with everything I've ever tried them on (as long as latency is set as 2ms).

I don't really use the K+DCAN anymore though.

[freebo86]

Well I tried it and it says Error Timeout Answer in D-CAN utility. The cable does nothing it seems like.

I took the cable back inside, soldered pins 7&8 hooked it up and it works fine it actually starts to read.. however I still can't read like my DME module etc. So it appears that simply unbridging these two pins doesnt' just work..

Whats a cable thats recommended?

[legoman67]

Ive never seen a blue K+Dcan cable. They are not the same as the blue VAGCOM cables. Vagcom cables do not have DCAN functionality and are actually built for Volkswagen.

Also, ive never used any accessory program to use Dcan, simply unbridged the pins and went at it. Never had an issue communicating with Dcan cars.

[lalaura]

i'm using green k+dcan cable switching mode from here (hope i not break the rule)

a small switch on it allows me to connect pins 7 (left) and 8 (right) for K Line and DCAN