From what I understand, the tire pressure sensors cannot be installed and used on aftermarket wheels. Does anyone know how to disable this system so I would not have to stare at a blinking light?

Thanks...

i have the tire pressure monitoring system and aftermarket wheels and my dash light isnt on

also, when removing my stock rims, there was no special connector or anything, just the lug nuts...so there cant be a wheel specific stock monitoring system

what I believe it does is monitor the rotation of the tires and flags any tire that is different (lower tire pressure)...that is just a guess...this would do the same with aftermarket wheels

I found this on the web:

" A. Indirect TPMSs

Indirect TPMSs typically work with the vehicle's anti-lock brake system (ABS). The ABS employs wheel speed sensors to measure the rotational speed of each of the four wheels. As a tire's pressure decreases, the rolling radius decreases, and the rotational speed of that wheel increases correspondingly. Most indirect TPMSs compare each wheel's rotational speed with the rotational speed of the other wheels. If one tire becomes significantly under-inflated while the others remain at the proper pressure, the indirect TPMS can detect it because that wheel's rotational speed is higher than the rotational speed of the other wheels. This information is conveyed to the driver by a simple telltale. The telltale indicates that a tire is under-inflated, but cannot identify which tire is under-inflated. Current vehicles that have indirect systems include the Toyota Sienna, Ford Windstar, and Oldsmobile Alero."

Seems to support what I thought about the 4Runner's TPMS. It works on rotational data...not actual pressure monitors in each tire.

ONLINE ARTICLE HERE

Here is another one that doesnt seem to like the "indirect" approach:

HERE

"C Indirect systems are only available on vehicles with antilock brakes, which are the more expensive vehicles on the highway.

C Because it measures differences in rotational speed of tires rather than directly measuring inflation levels, it works only if one tire is more than 25 percent less inflated than the others; the direct system, by contrast, provides continuous readouts on the dashboard in addition to warnings at underinflation levels of 20 percent, so that conscientious consumers can adjust tire inflation levels to keep them right at the recommended level, thereby preventing the repeated, cumulative damage to tires.

C Indirect systems do not work if all four tires are equally under inflated, a likely scenario if they are checked or purchased at the same time.

C It also does not work if two tires on the same axle or the same side of vehicle are equally under inflated, but does work if diagonal tires are equally under inflated, a shell game that is certain to confuse and frustrate consumers. By comparison, the direct system monitors inflation changes in all four tires and any tire combination.

C The vehicle must be moving for the system to work, so it cannot be used to check proper inflation at a gasoline station while consumers are inflating the tire and will only alert consumers once they are already on the road.

C The indirect system did not work well on the smooth surface of the test track, or on long, straight roads without curves. Enormous areas of the Midwest and West may not be well served by these limitations.

C The indirect systems were, overall, less reliable in notifying consumers of serious underinflation levels."

We have the direct pressure monitoring systems. The indirect are old news. FMVSS 138 is now law and all the automakers are using or going to use direct systems. Early indirect systems (ie. Ford) were thrown out due to lawsuits about reliability.

Maybe I'm completely wrong

but...how do we have direct systems when I have removed all 4 stock rims/tires and my dash light has not lit up?

Is there any documentation on how toyotas TPMS works??

This is great info Thanks for helping clear up this question!

24runners,
"...I have removed all 4 stock rims/tires and my dash light has not lit up?"
Let me guess. The tires are still mounted on the original wheels with the TPMS' and sitting in the corner of the garage (or anywhere on your property?) Go let the air out of one, start your Toy and see what happens. Your dash light should come on steady (indicating low pressure) because you are still getting a signal even though they aren't mounted on the truck. Now air it back up and get away from home for over 1+ hr. runtime. Then the light will start blinking (indicating a system problem, no signal, not low pressure.)
I have my winter wheels on and the originals are in the corner of my basement. If I travel away from home but only to work the 2-way commute is less than 1 hr (no light). If I go away for an extended drive the light starts blinking after ~1 hr. on the road.
Hope this helps.

Interesting...because my wheels/rims are at my parents house...several miles away from my apartment...and still no light..maybe I havent driven over an hour runtime...

sooooo....I guess this goes back to what was asked first....is there a way to disable this?

Maybe I'll get lucky and my light wont even come on *haha*

Thank you for correcting me

I learn more about this vehicle every day *LOL* and the majority of it comes from this forum!

"...because my wheels/rims are at my parents house...several miles away from my apartment...and still no light..maybe I havent driven over an hour runtime..."
Run the test anyway...air one down and see what happens. Does the light come on steady? If you leave for more than 1 hr. does the light start blinking?
I looked and can't find a way to disable it so I've learned to ignore the dash light when it starts to blink. The small pc. of electrical tape strategically placed on the dash bezel for the winter also helps

I am away from my parents house (which is on the other side of town) for days at a time...waaaaay longer than an hour...I'm not sure if the car has been ON and/or RUNNING for an hour straight tho.

Any idea what the "sensors" look like on the inside of the rim? are they detachable? maybe we could just put all 4 sensors in the storage area in the back so it wont complain about them not being near the vehicle *hehe*

Thanks for the info...I am going on a 4hr trip in a week and if I didnt know this, I'd probably think something was up if the flat tire light came on during my highway trip *haha*...Probably saved me a headache ;)

I have my OEM wheels and tires located in a garage as well, with winter tires and rubber valves on steel rims. For over a month driving around town, the TPMS light did not come on, but a 1 hour highway trip last Monday triggered the flashing light.

I have no idea what triggers the light, except that when it came on with my OEM tires, it indicated a low tire, due to a nail - the job it was intended to do.

Been there, done that with a flat tire.
Constant dash light on = low pressure (ie. flat)
Blinking dash light = system problem (ie. no signal because of distance away from stored tires/wheels)

24runners,
There is a pic on another thread. The sensor is integral to the valve stem (that is why the stems are metal bolt-ins.) If you take them off the wheels and carry them with you you would need to keep them in a pressurized container so they don't signal a flat. The system cannot be easily disabled because it is a mandated safety item just like airbags and brakes.

Kmvreter

Thanks...I searched for that thread and found it:

HERE

it answers a lot for me...nowwwww if I could just re-use the stock valve stems on the new rims.... *haha*

i am getting a set of 4 discoverer stt coopers installed on my factory 17"s ....will i have to have stems changed or do anything different? will my tmps monitors be ok?? is there anything i should be aware?