One problem related to check engine light on has been reported for the 2004 Chevrolet Avalanche. The most recently reported issues are listed below.
The contact owns a 2004 Chevrolet Avalanche 1500. While driving at unknown speeds, the low coolant and check engine warning lights illuminated. The vehicle was taken to the dealer, where it was diagnosed that the cylinder head needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 116,000.