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By mola
#197761
Dear Sir or Madame,

I have been using the SparkFun Car Diagnostics Kit to gather data from various vehicles, but I seem to have the same problem.
for some reason I can't connect and read data from any German car, or other cars that use that specific OBD protocol.
I receive an error to connect message.

is the SparkFun Car Diagnostics Kit comparable with the European OBD protocols ? or is the solution is to change the baud rate that I am communicating with ?

any ideas ?

Best regards.
By paulvha
#197772
OBD has 9 different protocols (so I discovered when 2 years ago I bought an OBD reader) To make it even more complex they require different pin connections (although they all share pint 4, 5 and 16.) The document http://www.alpha-bid.com/media/Shared-P ... tocols.pdf or the website http://scantoolcenter.com/obd2-basic/wh ... r-vehicle/ has some background information. The table on this website however is showing badly, but looks like this
PIN....2.....|......6.......|.......7........|....10........|......14.....|....15........|
|must have| --------------| ----------------|must have|---------------|---------------| J1850 PWM
|must have|---------------|-----------------|---------------|---------------|---------------| J1850 VPW
|---------------|----------------|must have |---------------|---------------|may have | ISO9141/14230
|---------------|must have|-----------------|---------------|must have|---------------| ISO15765 (CAN)

You have to make sure that your OBD cable is connecting to the right points. (the Sparkfun OBD-II to DB9 Cable seems to do that)

The STN1110 on the Diagnostic kit looks to support all the protocols with AT-command 'SP' (ELM327 page 24 of the data-sheet). I would expect the software that can be bought separately is setting this to auto (scanning the different protocols) or allows for setting the required protocol, But I have not experience with this board nor the software. (If you use serial or the Arduino sketch make sure to use ATSP0 command will set for automatic scanning or ATSP3 for ISO 9141-2 specifically)