One problem related to tank assembly has been reported for the 2008 Chevrolet Avalanche. The most recently reported issues are listed below.
Electronic door locks have failed on three of the 4 doors on this truck. Check engine light on due to code p0452, which is fuel tank pressure sensor defective. I called the dealership and they said it was not covered under the warranty and it would cost around $500 to repair. Spoke with my brother-in-law today who has a 2002 Avalanche and he had the same problem with fuel sensor and his repair was covered under the warranty. The door handle of my vehicle is plated in chrome. This chrome is now coming undone, and is razor sharp.