I had one of those and it turns out they don't have true four wheel drive, but rather an antilock rear differential. It is controlled by a sensor that can freeze in icy conditions and fail to engage. Living in Montana, we had to sell the otherwise perfect truck for something that could reliably get up our driveway in winter.

It was the TRD package that had the locking differential which was electronically actuated, right? But that’s entirely separate from the “true” 4x4 with the barrel drive shaft synchronizing the front and year diffs. Did you have a pre-runner? Some of those were sold with funky combinations that have the locking diff but a crippled 4x4 that disengages when you hit 10 mph.

Mine didn't have 4WD at all - don't need it where I live. My use case was hauling stuff in the bed and towing a boat. When I purchased the truck, it was one of the cheapest trucks with the towing capacity required for my boat.