New to the forum,probably a well saturated question,but can’t find answers
Have had the torque app for a few years,works great and love it.
years ago i bought a cheap adapter for a few bucks and works perfect,even on my 95 7.3 powerstroke diesel along with the ole lady’s dodge caravan
we live in Georgia but in Delaware right now for a while because my parents have some serious health issues and helping them out until they get better.
i left my adapter at home,so i thought i’d just buy a cheap adapter for 9.00 (ELM327) and when i got it,it would connect the bluetooth to the phone but would not read the computer on my wife’s 2003 dodge caravan(the one at home orks fine with it) or my new to me 1999.5 ford F250 7.3 diesel…
the seller gave me a refund with no issue at all ,they said since it was tried in different vehicles and doing the same thing on them it is defective…no complaints from there..BUT

I emailed a few selling these adapters and so far 3 of them told me the ELM327 does not work with diesels?…the one i have at home works fine
i am looking to get another,i use them keep up on my vehicles and i also want to check my parents 2006 dodge caravan..
what works for my diesel and the other cars?

My suggestion: For each vehicle that you want your OBD2 adapter to support, get in there with a flashlight and check the 16-pin OBD2 connector to see which pins in the connector are actually present. This will be the strongest clue as to which protocol(s) a given vehicle will need hardware support for (i.e. in the adapter). Some vehicles only use 1 protocol for all nodes while others can use multiple protocols (i.e. different ones for different nodes).

Once you know which protocols you need, you should be able to choose an appropriate adapter. At that point, it’s up to the software to do the right thing (assuming the vehicle supports what the software is trying to do — e.g. Capp777’s mention of possibly unsupported OBD Service Modes like Mode 09 and/or unsupported PIDs on the 1999-era diesel pickup).