Hey everyone,

Currently im doing a project to fetch the info from the car by OBD command via ELM327 with arduino Mega. My current stage is, I am able to communicate with ELM with the AT command yet when i connect it to the car and try to send the OBD command like "0100, 0101, 0105", all the response i got is error. The protocol used by my car is ISO 15765-4 CAN.

first i set the protocol to automatic:
>ATSP0
OK
>ATDP
Automatic
>0100
yyyyyyyyyyyyyyUNABLE TO CONNECT
>0105
yyyyyyUNABLE TO CONNECT

then i try to set the protocol to 6 (ISO 15765 CAN)
>ATSP6
OK
>ATDP
ISO 15765 CAN
>0100
CAN ERROR
>0105
CAN ERROR

The hardware connection is same as the one shown in ELM datasheet, hence i suppose theres no problem in the hardware. Does anyone know whats going on? it shouldn be the software problem as it able to fetch the reply of AT command. (the buffer of the response frm elm is set to 256 bits). I'm really stuck now.

thanks in advance for ur reply much appreciated!!