Takes some time to start up Sienna. Have to take out the key, put it back, wiggle it around, eventually it starts. When it just started happening, we took it the Toyota Dealer and they replaced the ignition switch (about a month ago). Then it started happening again very infrequently but we could not replicate it when we brought it back to the Toyota. Now it is happening more and more often but we still are able to start it up eventually and can't demonstrate it to the mechanic on demand. They checked all they could but need to be able to replicate it themselves in order to fix it. Any thoughts?
I've seen this issue when people put too many keys/items on the same ring as their car keys. The extra weight of these items swings back and forth when you drive, wearing out the ignition lock and key.
If your ignition lock was not replaced at the same time as the switch this is the culprit (they are separate parts).
The problem could be the immobilizer. If the immobilizer transponder or transponder chip in the key has started to fail, it creates such problems. Try starting with the spare key , if it is in mint condition.
Item no 9 is the immobilizer transponder ! And immobilizer chip is in your key