I'm using the Torque application on an Android tablet, with a bluetooth ELM327 module to connect to the car's OBD port.

When I turn the ignition switch to ON, the application recognizes the ELM327 module, but can not connect to the ECU.

Does anyone know which specific protocol the 2004 and 2005 S2000 use on the OBD (DLC) port?

Is is sufficient to have the ignition switch ON, or does the engine actually need to be running?

 

I had no luck with the ELM327 modules and finally bought a PLX Kiwi which works great with Torque. My phone connects as soon as I turn the key on.

 

I am not going to be much help.

However I have used ELM327 wired to my lapop running ProScan.

This is on a 2003.

Reason I didnt get the wireless is because it seems to have alot of problems according to many youtube comments I read.

 

Had no problems with mine but it has been a long time since I've used it and can't answer the OP's question off the top of my head and my AP2's an 06.

IIRC the ignition switch only needs to be on.