Smart key intermittent failure

Most of the time it is a weak battery but if you changed them the next most likely cause is a amplifier. Basically this is the antenna that picks up the keys. It is in the steering column so if these are faulty then you will need to hold it close to the column in order for it to pick up the key.

I am not positive but I believe the OEM scan tool (and compatible aftermarket tools) can monitor the signal strength. Clearly if we don't have this then there is no real way to test this as it is not a simple varying voltage signal based on strength. That means we probably just need to replace it and retest.

I attached the diagram of where this is but unfortunately they don't provide specific instructions on how to replace it but clearly we just need to access the ignition switch and it should be just behind it.

Looks like you would need to monitor the data in the key computer (transponder) or the body computer. I am not positive that this vehicle has the ability to do this but I know that this is the way to figure this out if you can. This is the way we determine this on most all domestic vehicles so Toyota is probably similar.

You are welcome. Let us know how it works out. Thanks