Does this happen with all Toyotas? I am looking at a 4Runner now, specifically because of how difficult my property and area can be to navigate.
Likely not as 4runnner is purpose built 4wd instead of a FWD with tacked on AWD like 95% CUVs on road besides Subaru.
There is so much Misinformation on this thread I do not even know where to begin, You obviously do not have a firm grasp about the 4 runners 4wd system, it is indeed disabled when the PCM has error codes, it works almost the same as the "tacked on" systems you speak of.
I do agree that disabling the VSC and TCS for an evap code is asinine. I do understand why you would want to disable non essential systems for something like a TPS code.
The ABS system is NOT disabled for a PCM code. Just the VSC and TCS.
I have two toyota products and find this ridiculous as well but I am sure the lawyers had the final input on the matter.
FWIW we have an awd sienna, an 05, there is always a 50/50 bias between the front and rear, there is no way to disable this, there is 3 differentials, a front, center ( not really in the center) and rear. All 3 are open. The vehicle uses the traction control to lock the spinning wheels. With No TCS you could have 3 wheels on ice and one on dry blacktop and you aren't going anywhere.
It is a quick, cheap and dirty AWD setup however it is also simple and extremely reliable. It is just not very effective if you do not have the benefit of traction control.
On My XB, it is almost undrivable with no traction control, the deep throttle tip in does not help. I for one actually like ABS,VSC and TCS. I have had plenty of vehicles without it and I feel overall it is beneficial.