One problem related to wiring has been reported for the 2012 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Toyota Sienna based on all problems reported for the 2012 Sienna.
2012 Toyota Sienna. Consumer writes in regards to acceleration problems. The consumer stated the vehicle started to stall. The more she attempted to accelerate, the speedometer continued to decrease. She was able to pull off to the shoulder. Her husband attempted to re-start the vehicle, but not happened. The vehicle was towed to the dealer. However, a computer diagnostic did not reveal a problem. Several days later, the vehicle stalled again. She managed to re-start the vehicle, and drove it to the dealer. After having the vehicle for several days, the dealer was still unable to find a problem. The vehicle was returned to the consumer. However, it stalled again, and it wouldn't re-start. The vehicle stalled again, for the 4th time. The consumer stated the technicians quickly found the problem, which was a faulty wire leading to the fuel pump. Updated 05/20/14.