[targa9]

This may be common knowledge to a lot of people on here but I thought it might be worth sharing my findings.

In summary I find configuring a USB K+DCAN lead works when set to 115,200 baud, no parity, 8 bits, 1 stop bit and all the buffer and latency settings at their minimum – but not reliably on all cars.

I have a suspicion that some protocols are only 100k baud so this might be too fast. Anyway yesterday I found out that was the case. On a 2002 E46 318i the ISTA-D comms almost identified the car then dropped out just before moving on to the error codes. To rectify the problem I set the baud to 38400 and it worked perfectly (57600 probably would have been OK but I didn’t try it).

What scares me was that ISTA-P seemed to be working at 115200 baud but I suspect it may have encountered the same problem when it came to actually programming something.

So my conclusion here is that if you’re using a K+DCAN lead on a variety of cars, some back the early OBD2 (around 2002), then use a baudrate of 57600 or slower.

A switchable USB K+DCAN lead also has an interesting capability I hadn’t expected:

Switched so the K lines are linked together it’s good for cars around 2003 - 2007
Switched so there’s a DCAN and K line it’s good for cars around 2007 - 2010
Switched so there’s a DCAN and K line it’s good for cars before 2003

For the record I’m running:

Windows 10 Home 64-bit
ISTA-P Loader V4.8
ISTA-P 3.57.4.003
ISTA-D 3.47.30