There are 2 other plugs near the one I am using. I'm using a plug labeled "Engine Diagnostics" and that seems to be working fine. The other 2 are labeled "ABS diagnostics" and "transmission diagnostics". Do those provide data I am not able to access? Also, The "Engine" and "Transmission" plugs each have an off/on toggle switch under them. The switches are off and information is sent to my VMSpc. Is there any reason I would need to flip the switche/s to "on"? (I have a 2003 Alpine with a Cummins ISL 400)