We had a similar incident with our '05 when it was less than 6 months old. Nothing happened when pushing the start button. I did not notice if the green light was on or off because it failed during daytime. Fortunately, the condition was not intermittent in our case. We had the vehicle towed to the closest Toyota dealer. After running some tests for an hour, they decided assistance from the Toyota engineers would be required and gave us a loner car to use.

Even with expert assistance, a full week was required to restore normal functionality. The service manager was both apologetic and cordial, and took the time to explain the apparent remedy to me in some detail. The part replaced to eventually solve the problem was the under-dash fuse panel. This made no logical sense to either the local technicians or I, since the fuse panel has no direct involvement with push-button start (at least according to the wiring diagrams).

Once a "fix" was discovered, they contacted Toyota to see if they should re-install the original (also-replaced) power control ECU, since it probably was OK (and it was a "$700 part"). Toyota approved reimbursement for the new ECU, even though the original one was likely good, so they left it in.

Later, I studied the wiring schematics to see if I could understand how the fuse panel could have been the faulty component. From what I could deduce, while the wiring diagrams depict the transmission gear selection switch ("PRNDS switch") as a mechanical switch, it is actually a solid state device powered from the reverse lamps circuit. The PRNDS device was not receiving power, so the start button ECU could not ascertain the transmission was in Neutral or Park, and refused to allow the engine to be started.

The next time you have this problem, try any of the following:
(1) "Jiggle" the shift lever while pressing the start button;
(2) Try with the transmission lever in Neutral instead of Park;
(3) Rap on the lower dashboard near the fuse panel while pressing the start button.

 

Thank you, I will pass along to the dealership and have them check out the fuse panel.

 

Curious JJohnson205...what did the dealer end up discoverIng with your problem? I have a 2007 Avalon Limited that recently started doing the same thing. I verified the battery was good, new key fob battery, checked the brake switch is functioning, checked all the fuses and relays (engine and dash), and took the neutral safety switch out to test it (appears ok). I’m scratching my head. The key fob buttons all seem to work (will activate the door locks and set the Immobilizer security system, pop the trunk, and sound the alarm). However, when I get in the car, the push button will not turn green when pushing on the brake (or) go into ACC mode at all. Basically, I’m currently a sitting duck with a locked steering wheel and no way to start the vehicle. The only things that I haven’t tested are: 1) Transmission Control Unit, 2) Engine Control Module, 3) Steering Lock Actuator Relay (under the shift lever), or the ECU’s (Main ECU or Immobilizer ECU). It seems like the car is not recognizing the key FOB for starting up (only), even though the FOB works for locking/unlocking the car ok. Very unusual. I’m guessing the ECU has a problem and it’s not allowing the transponder circuitry to respond with the other ignition circuits (brake light switch, and accessory mode circuits)? Not sure. I’ll probably end up having to get the car towed to the dealer to get it checked out. I can see my wallet shrinking already.