much ado about nothing...
The OBD-II spec on the connector (SAE J1962 and equivalent ISO/DIS 15031-3) specifies that pins 2, 4, 5, 6, 7, 10, 14, 15, 16 are defined and all the others are open to the manufacturer's discretion to use for whatever they please...
you are right in that pin7 is K-line and that 15 is L-line... according to these specs...
now the question is what is an L-line? well, during the ISO9141 days, it initially was used as a "wakeup line", so the diagnostic tool would wakeup the correct ECU with an address (normally a 5 baud address) on the L-line and there after all further comms would be on the K-line...
So after some time, the control units become more and more and the bus-loading of the ECU's became too much to handle on one line and many of the European manufacturers split the comms into two separate lines, and as the L-line already had most (if not all) of the physical capability (in most diagnostic tools) to handle said comms, the natural progression was to use pin 15 as the 2nd K-line...
now you have to remember that it is up to the OEM to do with pins 1, 3, 5, 8, 9, 12, 13 as they see fit... ons some of the older BMW *CARS* pin 8 was used as an additional K-line, on some of the Opels it was pins 12 and 13... but this was on cars...
BMW bikes never used the OBD-II connector till recently and all new bikes that do use it don't have a pin 8 at all...
HEX has been manufacturing Diagnostic tools since 2000 - for cars, mostly European cars, so the bottom line is that on the round 10 pin plug there are 2 k-lines, and if you use our OBD-II diagnostic tool (which has it's to K-lines on pins 7 and 15 so it can talk with Porsche, Bentley, Audi, VW, Seat, Skoda, Volvo etc), then we just have to make sure that our adapter connects those two pins to the correct pins 2 and 10 on the round 10-pin connector....
The result is that default diagnostic pinout is to have the two K-lines on pins 7 and 15 and that is what our tool does - remember we manufacture diagnostic hardware for *many* other brands too... for much longer than we have manufactured for BMW bikes and that's why *our* adapter for use with *our* HEX Diagnostic tools is the way it is... it is correct for *our* devices
Remember, the ICOM was specifically designed for BMW cars... and in order to get it to work with the 10pin round connector of the bikes (that followed later), they had to manufacture and adapter that would route the ICOM's K-lines to pins 1 & 2 of the 10pin connector... which is why it is the way it is....
Just for interest sake, pin 8 is used for a completely different purpose these days (enabling DoIP - Diagnostics over IP) - even on BMW vehicles...
hope that clarifies the issue...
best
Stephan
