4x4 Won't Engage - Brand New Tacoma - Looking for answers - Please Help

I hang out here, at a F150 forum and I used to spend a lot of time at a Jeep Wrangler forum. I've come to the conclusion that a large number of people aren't smart enough to understand how, and especially WHEN to use 4X4. The problems are usually operator error. Even when components fail, they usually fail due to operator error.

Not sure if AWD is the solution or the problem. AWD is a completely different system than 4X4 and is made for different uses. But for those who can't figure out when and how to use 4X4 that might be the solution. On the other hand the proliferation of new AWD vehicles has just confused people about how and when to use 4X4.

It is pretty common knowledge that all 4 tires have to be the same size, and pretty close to the same amount of wear. A reputable tire store won't sell you less than 4 new tires for a 4X4 vehicle knowing that the odd sizes can damage components.

But I'm not aware of anything that would prevent a vehicle from shifting into 4X4 with odd size tires. In old school vehicles doing so just caused excessive wear on the drivetrain. Perhaps the newer vehicles have an idiot proof system that will prevent the 4X4 from engaging. Perhaps the problem is elsewhere.