VAG-KKL ODBII>>USB - $15 K-Line cable

[TitaniumCranium]

First off I’m not going to take credit for this. This was derived from the folks at bmwecu.org. Reference links are at the end of this post. I’m going to show you what I did to get a working K-Line unit all in one post as opposed to the many posts I had to read to understand what had to be done. I found this information buried in a post by another member, Katvis. THANK YOU!

My test subject is a 2002 BMW 330Ci so I know it will work with E46’s and some other chassis between 1999 and 2007 that used OBDII and K-Line for communication. I can’t guarantee that it will work on all chassis in this time period because I am aware of some anomalies, but for the most part it will work. I've tested it and the cable will work with INPA and easyDIS. I have opened up NCS Expert and read modules with it but I havn't coded yet. Not because the cable won't do it but I'm still using training wheels

Search for VAG KKL on eBay and you should find quite a few cables available for around $15 shipped from China. I ordered the cable and surprisingly, 5 business days later, I had it in my hands.

Before you go any further, if you can’t solder or don’t know someone that will do this for a six pack of microbrew then you need to look elsewhere.

There are two things that must be done to the connector to make it BMW ready.

1. Pins 7 & 8 of the OBDII shell need to be shorted together
2. Pins 17 (GND), 18 (RI), and 20 (DSR) of the FTDI FT232BL chip all need to be tied together

On the OBDII connector side the BMW requires the following pins:
4 or 5 – ground
16 – +12 Volts
7 AND 8 - K-Line

Note:
Pin 1 of the OBDII shell is used for detection of +12V. By shorting pins 17,18 & 20 together this will send the message via USB that the system has +12V and that the ignition is on. This will show as Black circles in INPA. EasyDIS will believe that the ingnition is on. Voltage detection is still available via messages sent from the sensors on the K-Line and can be monitored in INPA.


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This shows the FTDI package and the pins. On the right-bottom corner is pin 17 which is ground. Pins 18 and 20 need to have a jumper installed on these pins.


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Here is the FT232BL chip before I made the modification.


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Here is the same FT232BL chip with the modification to jumper pins 17,18, & 20.


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This is the backside of the OBDII connector showing pins 7 & 8 before they are bridged with solder.


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This is the backside of the OBDII connector showing pins 7 & 8 with a solder bridge in place.


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Here is the finished product.

I hope this helps someone else out.

Here is where the original information comes from…
http://www.socalbavarians.com/bmwecu/viewtopic.php.htm
http://www.socalbavarians.com/bmwecu/viewtopic2.php.htm
http://www.socalbavarians.com/bmwecu/viewtopic3.php.htm
http://www.socalbavarians.com/bmwecu/viewtopic4.php.htm
http://www.socalbavarians.com/bmwecu/viewtopic5.php.htm
http://www.socalbavarians.com/bmwecu/viewtopic6.php.htm

[skipv]

Great writeup!!!! I am interested in using INPA for my 1999 E38 (build date 09/98). What cable do you suggest I purchase and are there modifications I must do.

Thanks in advance for your help.

[TitaniumCranium]

To be completely honest I only have experience with the E46 chassis. I have read quite a bit about earlier model chassis but only in an effort to figure out which cable I needed for my application. It's possible that this cable would work if your car has the 16-pin OBDII connector. If it also has a 20-pin round connector under the hood then I can't be sure if it simply requires an adapter or the ADS plug as well. Hopefully one of the more seasoned members can weigh-in.

[David Mc]

This cable will not have full diagnostic capability on any car that requires ADS functionality. ADS means that the car communicates via both L and K data lines - just because your car is fitted with a round 20 pin port, does not automatically mean that it requires an ADS interface. If however the round 20 pin port has a metal contact fitted to pin 15, the car does require an ADS interface and serial connection to a computer.

[cer54467]

I have a round pin connecotr and a RL chipset in my connector, doe sthe voltage have to be inverted? I had read soemwhere that the voltage on 7-8 has to be inverted. can some one help withthis?

[TerraPhantm]

This cable will not have full diagnostic capability on any car that requires ADS functionality. ADS means that the car communicates via both L and K data lines - just because your car is fitted with a round 20 pin port, does not automatically mean that it requires an ADS interface. If however the round 20 pin port has a metal contact fitted to pin 15, the car does require an ADS interface and serial connection to a computer.

Doesn't the "KKL" imply that this cable is a dual k-line and an l-line cable?

[cer54467]

I do not know, I was trying to find the other post regarding this mod, I have yet to get full gt1 and sss up and running, I have VM installed & everything Dl'd and iso's created but i have not doen the install yet.

[TitaniumCranium]

I do not know, I was trying to find the other post regarding this mod, I have yet to get full gt1 and sss up and running, I have VM installed & everything Dl'd and iso's created but i have not doen the install yet.

At the end of my first post I gave reference to the posts on bmwecu.org where I obtained my information. It's a long read, six pages of posts, but they pretty much covered every aspect of this cable. I don't recall them saying anything about inverting the signal for 7 & 8. There was some discussion of having to route one of the other pins to pin 15 of the round connector IIRC.

While I didn't do this to my cable there was also discussion of using an NPN transistor and a resistor to generate the proper voltage detection and ignition-on signals to pin 1 of the OBDII connector. Doing this, DIS (easyDIS) will correctly sense the voltage and ignition state so that you can use the diagnostic routine sections of DIS.

OBD2 has the following standard I/F:

*edit* for models younger or older than my e39 this may be different, so check your schematics. Older, non-OBD2 models may work with adaptors, whereas some new models even seem to use pin 7 only, i.e. require no mod at all (see all this in the many posts below)

Pin 1 - Kl.15 (+12V with Ignition)
Pin 2 - J1850 Bus+
Pin 4 - Car GND
Pin 5 - Signal GND
Pin 6 - CAN High (J-2284)
Pin 7 - ISO 9141-2 K-Line I/F
Pin 10 - J1850 Bus
Pin 14 - CAN Low (J-2284)
Pin 15 - ISO 9141-2 L-Line I/F
Pin 16 - Battery (+12V)

Volkswagen (VAG) "KKL I/F" uses 4 (or 5), 16, 7 and 15, i.e. TWO bus lines (7 & 15).

The BMW(!) I/F only needs ONE bus line on BOTH pins 7+8, i.e.:
- 4 or 5 for GND
- 16 for +12V
- 7+8 for K-Line

AFAIK, K- and L-Line are electrically equal, so whether for you the wire connected to pin 7 or the one connected to pin 15 of the original I/F will work better may be a matter of the allocation of signals to the USB port/protocol (?) or different internal pull-up resistors only.

IMPORTANT:
Test I/F with EDIABAS/INPA first, since that S/W is not expecting anything else than these "simple" I/Fs as input. Select "OBD" I/F during install.

NOTE:
GT1/DIS is different! It additionally requires a piece of S/W called "protocol converter" on top of the original GT1/DIS S/W to work with these kind of "simple" (non network) I/Fs, so no luck w/o e.g. easyDIS!

[Reefin Dude]

Ok, trying to figure this whole cable thing is crazy.

please correct me if i am wrong. having a OBDII only car (02 540it, it does not have the ADS port under the hood) this USB cable should work with the mods on my car, correct? i have access to many laptops, but i have a small USB only laptop i would like to use if possible instead of the larger D630's i have lying around. is the USB limitation a part of the ADS communication through the EDIABAS or the EDIABAS itself? can an OBDII only vehicle use USB to OBDII cables and get full functionality of these software?

Thank you,

G~

[jht3]

your '02 only uses the OBDII port, so this cable w/ mods and a working USB port on a laptop is all you need.

ADS requires a fully functional serial connection (from what i hear). but that doesn't apply to your car.

[Reefin Dude]

thank you for the confirmation. from all of the reading i was doing this looked to be the case, but just was not sure.

G~

[KevinMullins]

This thread may help - http://forums.bimmerforums.com/forum....php?t=1505990

Inverting of two pins (via software) is needed if you have the FT232RL chipset in your cable.

The transistor/resistor mod is if you want "true" ignition on recognition. Jumpering the pins on the chip just tricks it to think its always on.

If you have the 20 pin connector under the hood you may have to jumper a few pins there when using the OBD cable. I recommend just getting a 20 pin adapter to USB and using the port under the hood.

If pin 15 inside the 20 pin round connector is populated AND has live voltage, then you will need an ADS interface to get full functionality.

[e30hijinks]

I have an ELM327 cable. I searched but couldn't find anything. Could I modify the ELM327 per the above instructions and get it to work for coding via NCS Expert on my 2002 E46 330? Or do I need a specific eBay blue KKL cable? They look the same...

[PDPR]

I wanted to put a small contribution to something that I've found that can make it easier welding pins 17,18 & 20 on chip FT232BL, VAG KKL blue Cable.

Due to the great thickness of my soldering iron I found it very difficult to properly weld a cable just on Pin 20 (DSR) on the chip FT232BL, so, with the help of a multitester, I started to look for an alternate place on the circuit board in contact with this 20 pin... This is my surprise I find that the pin 20 and 21 are connected together, which means that you can be welding the cable between both pins without any other consideration! Done and working. I guess this is the same for all blue-type cables, but I wish if some of you could double check and confirm here that it is.

Another suggestion is that if you carry out the welding of pins 7 and 8 on the OBD connector, you may have to caution that they do not fall out/move and if it happens that you have to carefully reinsert/move especially the pin 7, it is very easy to break the circuit board track (8 has no track) and the cable will not work

[TitaniumCranium]

Since you may be looking for the solution to know what the chip configuraion is in your working "clear" vag head against the ones that works, this is for you.