evsnova74

Another P0449 code

I have a mostly full understanding of what's going on with this code, the only problem I have is I don't have a tech 2 or other way of forcing the circuit on to test it. Without just throwing a solenoid at it and hoping that's all it was, does anyone know when the ecm sends power to the solenoid? Like perhaps start the engine, then within 5 minutes the test light should turn on or something like that?

2018 Express 2500 6.0l if that matters

mountainmanjoe

For the benefit of anybody trying to help, DTC P0449 means:
Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction

mountainmanjoe

Well you could put 12V directly to it. schematics should be on gmupfitter.com

it's only 20 bucks. Not the end of the world.

Always

You can start with the troubleshooting procedure here: https://www.obd-codes.com/p0449

evsnova74

I don't have a problem spending 20$ I just wanted to go about diagnosing it the proper way instead of "throwing parts at it".

The fuse was good, and the old solenoid clicked when given 12v so I guess it's a break or short in the wiring somewhere. Which is weird because everything seems like it's in great condition. 78k miles, it had 30k when we bought it. Compared to everything else we've had it's virtually brand new lol. But I didn't see any chafing or the like so no idea why the wiring would be faulty.

But since I had it I did put the new one on, didn't have my Bluetooth dongle on me so couldn't clear the codes. Maybe I can use hptuners to do that, see if it comes back.

mountainmanjoe