TPMS -- why not on spares?

Don't know, but I would check other sources

 

You can buy a set of programmable TPMS sensors like Autel Maxi TPMS and clone sensor IDs from existing OEM sensors. In theory, it let you swap summer and winter sets and the car treats it as if nothing has happened. I have not used them myself, but there have been several threads on it. Some reported problems with cloned TPMS not being identified by the car.

Even with programmable TPMS, you still need to bring the car for the initial programming of the clonable TPMS sensors at a tire shop. Dealers will not likely work with aftermarket programmable TPMS, and OEM TPMS sensors can not be programmed to copy existing TPMS. If you want all of this DIY, you must invest in the TPMS Programming tool. Or you can buy a tool like ATEQ Quickset to DIY the reprogram car ECU each time you do the swap with a different set of IDs.

 

I was going to say, my Dad has a RAV4, the last model year that they actually put the full size spare on the back of the hatch. And I know from his experience that it does have a TPMS monitor.

Overall, TPMS isn't going away.
I'm going to say, I think it NOT being on most spares is because of the compact size of the spare being a entirely different required pressure range.

My Honda Fit has an indirect TPMS system. Which uses the existing speed sensors in the tires to trigger alarms. It's not directly monitoring actual tire pressure.
The advantage is, I can switch tires, rims, without needing new sensors. I do have to re calibrate after any change.

 

Yeah give your head a shake; you don't want that.

Yeah Mazda's like that too. Toyota has to catch up...

 

It is possible that they used clone-able sensors, in which your existing sensor IDs are programmed/copied into the new sensors. This abolishes the need for reprogramming the car whenever wheel sets are swapped.

It would be nice, and quite possible, for a car to remember 2 whole sets of TPMS sensors. But my five year old Forester does not.

There is no frequency change. Rather, it is a code number change.

 

There seems to be two main disadvantages of indirect TPMS. It takes time for the car to get a measurement; the system is comparing wheel speeds during turns. So you can be miles away from home before the system gives an alert. With direct sensors, I got a low warning while still on surface streets, with indirect, I might not get it until I'm on the highway.

The other has to do with it not actually reading tire pressure. Tires slowly losing air all the time, and at about the same rate. All four tires on a car with indirect TPMS can become under inflated without a warning from the system. The regulation calls for a warning when tires are 25% under the manufacturer recommended pressure. I don't see how these systems are legal. It seems the car companies apply for an exception. Indirect TPMS still requires the driver/owner to regularly check tire pressures. If that were the norm, TPMS wouldn't be required in the first place.

Direct vs Indirect TPMS
Tire-pressure monitoring system - Wikipedia

 

I avoided the details, well, because this is PRIUS chat, and I figured nobody really cared about how I felt about my Honda Fit indirect TPMS system.
But yes, there are advantages...and IMO disadvantages to indirect.

What I REALLY like about my indirect system, is the ability to ignore it. That is...I don't have to change sensor batteries, pay for any new sensor set up or calibration with tire or rim changes.
Basically, if the light comes on, it's just check your tires air pressure...if it's OK....do a real simple self initiated re-calibration process IE: Press a Button, and keep driving. That I really like.

What I don't like?
Is yes, my specific experience is the indirect is not as reliable as the direct.
With my TPMS? Like clockwork, if I go on a long highway drive...that is highway speeds for an 30-45 minutes or longer, I will get a TPMS alert.
And what really sucks about it, is you can't or shouldn't ignore it. Which means I keep a high quality Tire PSI gauge in my vehicle, for that inevitable point where I have to pull over to check, to make SURE the TPMS alert is not real, and just it's usual quirk.

That never happened with my Prius, or any vehicle I owned that had the direct TPMS system.

But I really enjoy the fact that I don't have to worry about all the peripheral problems that direct TPMS creates. If you change tires or rims, or if the sensors get damaged or eventually the batteries die.

So it's a trade off. But at least in my case, the indirect system hasn't been "perfect".

The Fit, is a entry level Honda Product. I'd be curious if more expensive vehicles with indirect TPMS had the same symptoms.

 

I checked into the Mazda sensors a bit, with our son having a CX-5. They're similar to Toyota, in each rim, incorporated with the tire valve. I'm not sure, but I believe a Mazda dealership might have to do an initial "handshake", but from there on, say swapping between all-seasons and snow tires, a few minutes driving above some speed threshold (around 25 mph'ish), and the swapped in sensors are recognized. I looked up an online Canadian dealership source for the sensors: $30 (CDN) apiece.

Apparently pretty much cross Canada, Mazda has a snow tire promotion in the fall, offering snow tires on compatible Mazda steel rims, with sensors, centre caps, installed. IIRC correctly, X-Ice package for CX-5 was around $1500 CDN.This kind of turn-key offering is refreshing.

 

In preparation for getting dedicated winter wheels and tires for our SUV, I just ordered AUTEL MaxiTPMS TS508 service tool. I intend to use it for our Nissan Pathfinder Hybrid SUV, but the kit I bought includes programmable sensors. When I have to mount a new set of tires on my PRIME's winter wheels, currently without internal TPMS sensors, I will try cloning the TOYOTA OEM TPMS sensor ID's.

 

Let me know how it goes. I am in the same boat.


2017 Prius V Five | 2010 Volvo XC 90 3.2

 

Sure. The only thing is I bought new winter wheels and tires for my PRIME last year. This is only the second season on them. Unless the tires need to be replaced prematurely, the next tire change will be 3 years in the future. I may use the sensors I got in the kit for my son's Honda before mine.

 

Isn't there a Standard - Imperial button somewhere? Or did you buy your Outback way outback, north of the border?

 

Don't try to pin bars or whatever on us. All I've ever heard is PSI. Maybe in Europe??

 

Vancouver is a bit mystifying when it comes to malt and barley drinks. A pint is seldom a pint, a pitcher can be a jug, and a sleeve is not what you wipe your mouth upon, rather something that may or not approach being a pint. To fess up, I haven't crossed the northern border since they started requiring passports back after the terror attacks in 2001.

 

Well that head gear would get you pulled out of the line for closer inspection, lol.

I don't get out much, was a little nonplussed the first time I heard "sleeve". Sounds vaguely like a meth envelope too????