Sparkfun CAN Shield BMW OBD2 reading I bought the CAN-Shield from Sparkfun https://www.sparkfun.com/products/13262 and I also got the Uno from Sparkfun just to be sure everything works fine.

Some info about my car:


BMW E91 2006
OBD2 is available
KWP 2000 and other lines are available
like the ones with the same baud rates from the demo 


I tried the SparkFun_CAN_Demo which is available on their website and GitHub. 

My output is that 
CAN init is successful but I don´t know if that´s true...
If I try to read the RPM, for example, I get a buffer with a size of 1 -> " ".

My questions are: 


Did I something wrong with the MCP2515 how do I know if it´s dead? 
Does anybody know if the demo is working properly or not? 
What´s the right way to get data from an BMW with OBD2?
First off I cannot say much about the library that you are using I have't tried that one yet as for the shield i have some of those and there are two versions of them check your PIN outs on them the cs pin is either on d9 or d10

the other thing is make sure that you are in the right operation mode ie. Normal and maybe give this library a try I have had lots of success with this one:
https://github.com/coryjfowler/MCP_CAN_lib

as for the baud rate I have tried all types of ways of getting the right baud rate for certain vehicles but the best remains start small and step it up till you get the one that gives you reply 

make sure that you ground the Arduino to the car as well it works without that but sometimes it does nothing If you are using the OBDII cable it should be grounded by default