One problem related to transmission failure has been reported for the 2006 Toyota Avalon. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 Toyota Avalon based on all problems reported for the 2006 Avalon.
Transmission randomly fails to downshift when accelerator depressed half-to-full to gain speed quickly for merging into traffic, etc. At times, downshift simply does not occur, other times there is a one-to-two second hesitation before the downshift/acceleration occurs.