One problem related to electrical equipment has been reported for the 2006 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 Toyota Sienna based on all problems reported for the 2006 Sienna.
Master head unit, including navigation, rear camera, bluetooth, and stereo, stopped working. It makes a clicking noise but the screen is dead and does not respond at all. Appears to be from a design defect that causes overheating of the unit over time. Multiple reports of similar failures are all over the internet. This is a significant safety issue as the rear camera, bluetooth, and navigation are all important items for extra safety in operating the vehicle. I think most people would expect that a non-mechanical part (like the radio/head unit) would last longer than 6 years, especially when it cost several thousand dollars.