The thread about adding a locker to a 3rd Row SR5 (as opposed to adding 3rd row to a Trail) got me thinking about the following:

My impression (which could be wrong) of the MTS is that it exists only as software and a selector knob that selects different "modes" for ABS/TRAC. If this is correct, and assuming that there is not a separate or different control module in the TE then does anyone know if it is possible to easily add the Multi Terrain Select to an SR5 thru a wiring mod and adding a selector? This might be more trouble than it is worth as I'm sure that many here do not even use the MTS if they have it. Does anyone know where the MTS gets is processing from?

the biggest problem will be swapping out the computers that make this happen.

if its not programmed into the computers, it will get real $$$ really quick to the point of "you should have just bought a TE and figure out on how to add an aftermarket 3rd row.

MTS is probably not worth the effort. It just doesn't do all that much. If it's just a switch it could be easy enough to do, but I kinda doubt it will work.

It will likely take an ECU swap and then switching. I'm guessing the $ is going to be more than a rear locker - which is a lot more useful IMO. I am curious though if it work. Crawl control is the function I'd much rather have than MTS since you already have atrac.

Does the Trail have the mounting points for seats or seatbelts? If it doesn't, I wouldnt feel safe mounting seats and belts to sheetmetal, and expect them to hold during a crash. It for sure won't have the side airbags. Aftermarket seats are likely not going to be safe (My opinion, I haven't done research but my common sense tells me so).

If you really need a 3rd row, just get a SR5 and add a locker if you feel you need one...

I could see multi-terrain select being useful, but with the standard ATRAC and a rear locker, it isn't really going to make a difference, and won't be worth the cost of adding it, if it is even possible. The Crawl control is useless too. It is so obnoxious to use, with the constant triggering of the ABS, that you won't use it. Just use 4LO and put your trans in S, to contol your top gear.

Got it- I currently have a 2015 SR5-P w/3rd row.. The main reason for asking is that if MTS control is in the ECU already and unused then maybe someday I would look at adding a selector, but not if it required any more work or cost than that... Obviously the time/money could be spent in better places if it required a new ECU or MTS specific electronics.

Not worth the (any) effort. Just turn on ATRAC and call it a day.

Probably not doable and totally not worth it. Toyota locks everything down and encrypts....

Also, MTS is a feature that is not really very useful in the real world.

Everyone who I know locally that has a trail with it...says they have never used it and find it completely worthless on the trail. They say it is impossible to tell if it is making any difference at all. ATRAC is all you really need.

You would be much better off spending your time/money on tires or ground clearance.

I'm sure someone will chime in saying it is the best thing since sliced bread... If you want to do wild stuff off-road get select-able lockers. It is really the only way to go and have the predictability you need in extreme conditions. ATRAC is great, but it's not predictable or graceful enough to give the driver the control that is needed on extreme obstacles. It's great in simple slick conditions and sometimes better than lockers on off camber wet/slick ground. Less crabbing than lockers in those conditions.

Bottom line, best 3 upgrades possible in order 1. Tires 2. Ground clearance (lift) 3. Lockers

There aren't enough in junk yards yet - but rest assured. If you wait a few years, you'll find rear axles complete for about $1,000 and you can do a bolt in swap into your SR5 and just worry about some wiring if you're not happy with the ATRAC. ARB lockers are of course the other option - and basically the only option for the front. Toss a locker in both ends and it'll go pretty much anywhere you point it.

For my list of upgrades, I might switch around just a little, but I'd go 1. winch 2. rear locker 3. lift/tires 4. diff gearing 5. front Locker