They are external to the canister and replaceable.This just happened to me a few days ago. i have a 2005 DC Limited and i have found that if its not the rubber parts of the hose in the engine compartment, or a loose gas cap, it could be a switch or solenoid on the CHARCOAL CANISTER. A new canister is about $500. Thats IF the switch is built in the canister. i personally dont know if it is, and i havent had time to take a look.
doees anyone know more info on the canister or had this problem?