obd2 port Doesn't work?
So i've been trying to get the obd2 to work on my 04 silverado. the scanner doesn't use batteries, and it turns on when i plug it in, so i'm pretty sure it's getting power, but whenever i try to read codes, it says "communication error". i've gotten it too work in the past by fiddling with the connector enough, but today it just wouldn't work. I also checked all the pins on the connectors, and they all look good. I've also tried testing it on a different vehicle, an 04 sierra, and it did the same thing. all the other vehicles i've tried have worked fine.
I've gotten it to work in the past, so i'm pretty sure it's compatible.
So today i got both of them to work. Apparently the engine has to be running for it to work. That's probably what made it work last time. Anyways both trucks had an "evap system test failed". Kinda weird.