Thanks for your reply,
First, as far as I know, the total resistance of the bus should be 60 ohms, thus we usually put 2 120ohms resistors on the ends , 2 parallel 120 ohms results total 60 ohm.
please refer to :
In the MCP2515 CAN bus monitor the 120 ohm resistor connectivity is determined by a FET transistor , which is controlled by the PIC18 MCU ,
So I decided to skip this part, and try to sniff the OBD2 port of my car.
I'm using Togglebit OBD2 cable from :
I connected the wire by colors :
CBT orange to wire green/black ,
CBT yellow to wire white/black ,
CBT green to wire blue/black,
CBT blue to wire yellow/black
I didnt connect the ground or power wires (Do I need to do that?)
I didnt add 120 ohms resistor, since I thought that its not needed when you connect CBT to a car bus.
The CBT couldn't detect any bus ( I used the serial API) I run the command :
I know that the serial commands work because I get info for 0101
Do you have any idea?