I have a guy at work that has a '07 Sierra 4.8l.

It recently popped up this code, P0449, EVAP CONTROL CIRCUIT FAULT..

I checked for 12v in the Pink Wire on the EVAP Solenoid Connector and it was good, changed the Solenoid, Fuses are good. I cleaned the PCM Connectors and there were fine before I took them off..

I put it on a Scanner and cleared the code, then started logging it and the code came back. I then cleared it again and manually commanded it on and off, and it worked. I turned it on and let the PCM do it and it throws the code.

I think it's the Wire going from the Connector to the PCM..unless anyone has any other ideas?

Thanks.

 

very common problem.... you need to install new valve and relocate the filter to above the trans with 5/8 heater hose. There is a bulletin in SI about it, but it isnt working right now.

 

+1, I'm familiar with this TSB, as mentioned this is a common problem

 

K. What Valve and what Filter do I have to move around?

 

You'll need a new Evap Vent Solenoid Valve. It comes with a new designed remote mounted filter. You'll need to use a few extra feet of hose. I re-mount the filter up around the drivers side near the transmission. That way no water and road dust and material will be taken in. Trust me, just like Budhayes said, this is common as the day is long. I do at least 3 a week.

 

an 07??? IS that still covered under the factory warranty... I believe federal emission laws would at least cover it.

 

The evap vent solenoid, valve and charcoal canister are not part of the Federal Emissions Warranty coverage. They purge the air from your fuel tank, not remove hydrocarbons from spent exhaust vapors. But however, if the truck has less than 36K miles on it, it should be covered under the 3YR 36Kmile bumper to bumper warranty.

 

TorqueWrench is correct again...we have a better warranty at Lexus than GM (4/50), but after 50K, the customer's paying for EVAP repairs.

 

Good to know! I was not aware of that.

 

I have this exact problem on a 99 that I just bought, but I am curing the problem by completely removing the EVAP system, purge valve, vent solenoid, and canister. If you can program it, just remove the codes, and run said heater hose from the tank vent line to a safe location where moisture and debris won't be able to enter the tank and you'll be golden!