Two problems related to cruise control have been reported for the 2008 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 Toyota Sienna based on all problems reported for the 2008 Sienna.
I accidentally hit the cruise control in my 2008 Toyota Sienna when the control lever was over the windshield wiper control in a slight left turn, resulting in the cruise control going unexpectedly into "resume". Because of inclement weather I had slowed down and was not expecting the instant acceleration. Took a couple seconds to realize what had happened when I had tried to operate the windshield wiper control. The Toyota cruise control lever mounted on the steering column where it turns with the wheel appears to be a less than desirable engineering decision from a safety standpoint. Trying to express this concern to my local Toyota dealer, (pine bluff, arkansas, where I bought the car) was unsuccessful. I had been trying to be helpful with Toyota's more generic problem of a complaint of uncontrollable acceleration, which Toyota has been trying to blame on improper floor mats being jammed into the accelerator pedal.
The contact owns a 2008 Toyota Sienna. While driving 35 mpf with the cruise control engaged, the vehicle began to reduce speed when the senor recognized another vehicle approaching. The contact stated that whenever a vehicle in front of him changed lanes, the vehicle accelerated to the set speed. The contact is concerned about the safety risk involved. The contact took the vehicle to the dealer who was unable to diagnose the failure. The contact would like for the manufacturer to have the laser sensor removed. The failure mileage was 1,000. Updated 03/17/10.