Only reason I'm posting this after reading the search results was because it actually went off on it's own and then came back on.

Not sure if it's a coincidence or not, but after getting the new transmission installed, 2 days later I get the SES light and get the above code. It is an Evap emission control system malfunction.

here's some of the info I got off the GM site: This DTC will detect a weak vacuum condition (large leak or restriction) in the EVAP. system.

I went and read and cleared the code on Tuesday. came back on Thursday. I drove 280 miles to PA on Friday and about 200 miles into it the light went away. Warm and hot all weekend, never showed up. Went through some rain and around that same time it popped back on. Not sure if the weather and new tranny have anything to do with it (tranny is a little high on fluid). Just curious how it went off all by itself after a while and then popped back on. Any ideas?

Andrew

 

Check that gas cap!

It might be time to get a new one.

Also, since the fuel/evap lines run next to the transmission (driver side) make sure there are no kinks or obvious problems first.

 

The evap can and lines run right beside the tranny on the drivers side. With a tranny swap very possible to have messed something up in the area.

 

Got under there and think I found my problem. Plastic purge line out of the evap canister has a hole. Probably residual damage from the driveshaft explosion. Think I can put some silicone to cover that hole or you think I should replace that little plastic line? It doesn't see any serious pressure so I think the silicone would work.
Andrew

 

I'd probably just replace the line especially with anything related to fuel. And it might be important depending on how **** your state is with Emission testing.

 

Or you could cut the line and try clamping some fuel line or larger vacuum hose over it....

 

just caught this thread, my truck has set these codes lately also, ive had my trans out also and will be checking the hoses and gas cap. Great help here guys!!