KR Kodi

iTrader: (1)

There have been a lot of posts about owners that have put on a new set of wheels that have a different set of tire pressure sensors than were in their original wheels/tires, and in many cases they say aren't getting any lights, dings, or messages of TPMS problems.

Many people seem to think that if you put on a different set of wheels with different sensors, or get new sensors installed in the wheels on your truck, and you don't get any lights or other indications of TPMS problems, then the truck somehow automatically recognized the new sensors.

Butt.....that's just not the case.

There are some vehicles that will automatically pick up the signals from new or different tire pressure sensors, but our F150 trucks do not do that - nothing happens automatically with our trucks as far as logging new tire pressure sensor ID #s into the memory of the TPMS computer in the truck.

The TPMS computer stores the unique ID #s of the 4 sensors that are in your truck's wheels. That way when you're driving down the road next to another F150, and your TPMS receives signals from 8 sensors, and the other truck has low pressure in one of its tires, your truck won't give you a low pressure indication - your TPMS only pays attention to the signals that contain the ID #s that are logged into your TPMS memory.

Same if you put a different set of wheels on your truck with different sensors. Unless you log those sensor's ID #s into your TPMS, your truck will not recognize the signals they transmit.

So....how do you do the "relearn procedure" that will log a new set of sensors into your TPMS???

BTW - if you have one bad sensor and get just one new one, you still need to do the full relearn procedure.

You need to put the truck into the "learn mode" where the TPMS is setup to log the sensor ID #s into its memory. Each model year may have a slightly different method, so read the manual for your model year.

After the truck is in the learn mode, you need to get the sensors to transmit their data to the TPMS - and the Owners Manual procedure to "trigger" them (force them to transmit) is to change air pressure in the tire by letting air out.

When the TPMS is in the learn mode, and it picks up the transmission from a sensor, it gives a confirmation honk of the horn that tells you it received the signal and stored the sensor's data in its memory.

However, there are TPMS tools that transmit a VLF (Very Low Frequency) 125 kHz signal that triggers the sensor.

In a thread about sensors in the "Aftermarket Products - Wheels and Tires" section of the forum, member Steve Osborne had a picture of a small TPMS tool that transmits the triggering signal. I have one of those tools, so I made a short video of the relearn procedure to show how simple it is.

You can get the tool for around $40 on eBay (do a search on eBay for "Ford TPMS tool").

If you want to do the method of changing air pressure, you'll put the truck into the learn mode, then instead of using the TPMS tool you'll just let air out of the tire until you get the confirmation horn honk. Of course you'll need a compressor to pump your tires back up to normal pressure afterwards.

There's a link to my YouTube video below.

Bob



BTW - below is a picture of a more sophisticated TPMS tool that has a screen. This tool has a receiver that picks up that signal transmitted by the sensor when it is triggered, and the sensor's data is displayed on the screen. This is a great tool for doing diagnostic checks of sensors when you have TPMS problems. You can see it shows the sensor's ID#, the tire pressure, the temperature in the tire, the condition of the battery in the tire pressure sensor, and the frequency the sensor transmitted on. Why at least this pressure info isn't displayed on our truck's instrument cluster display, I dunno!?!?

This is one of the sensors in my 2013 F150:



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gsxr1216

Well i will have to disagree some stuff in your post.....

i have a 2012 once spring came in 2013 i bought a set of "summer" wheels for it with no TPMS in them. Every morning i would get the tpms error on the screen and a bunch of dinging ETC and after 20 minutes or so of driving same dinging and warnings again. Fall 2013 i put the OEM wheels back on no more error messages at all.

So this spring i decided to buy TPMS for my summer wheels as i was not going to go through another 6 months of warning and dinging. So i took the wheels to a shop has them broken down and the sensors installed in them. A few weeks later put them on the truck and here we are 2+ months later and i still have not had a error message at all. The truck sees the new sensors somehow, not sure how but it does in my case as it has never tripped the light or dash warning with them yet in 2 months.

FWIW my wife's car has summer and winter wheels both with TPMS and i have to reprogram that car 4 times a year to keep the light off....

KR Kodi

iTrader: (1)

Excellent!! I'm glad your truck works differently from mine.

The problem with your truck is that when you pass that other F150 on the highway, and he has low pressure in a tire, your truck is going to pick up the transmission from his sensor and you'll get a low pressure indication in your truck. When you pull over to check and find your pressures are all okay you're going to wonder WTH is going on!

Actually, what is probably really happening is that your other set of wheels is probably stored within a couple hundred feet of where you park your truck. The truck's TPMS is picking up signals from those sensors, which is keeping the light out.

Have you gone on any longer drives with the summer wheels yet? I don't know what period of time our TPMS takes before it realizes it's not getting transmissions from the sensors (because they're stored back in the garage), but I suspect it's probably an hour or so. After some period of time and the TPMS doesn't receive signals from the sensors whose ID #s are stored in the TPMS memory, you'll get a message that says to check your TPMS. The truck thinks that if it's not receiving any sensor signals at all that the TPMS must be the problem - nobody would drive with no sensors in all 4 wheels, right!?

The pressures in your winter tires are stored in the TPMS right now, and until you drive for quite a while, those old pressures will keep the TPMS satisfied and keep the light out.

One thing that will drop those old pressures out of the TPMS is to disconnect the battery. Disconnect your battery for a couple minutes, and when you reconnect it I suspect you'll have the light, although if your winter tires are close then those sensors could transmit their pressures and keep the light out.

One way to check for sure is to lower pressure in a tire on the truck down to about 20 psi. If you get a low pressure indication then your summer tire sensors are indeed being recognized by your TPMS - however, I'm quite sure you won't get a low pressure indication because the TPMS just doesn't recognize those summer sensors because they're not logged into your TPMS.

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gDMJoe

BTW ... The TPMS sensors used in the F-150s are NOT unique to just the F-150s. They are common across the entire FLM lines. Though there are band and stem varieties and each has its own frequency - 434MHz (band) / 315MHz (stem). 2009+ are the stem variety.

BTW ... Passing another F-150 (or any other vehicle for that matter) on the road does not interfere, confuse, cause a mis-read (or read), etc., etc., etc..

BTW ... Having another vehicle or wheels "stored within a couple hundred feet of where you park your truck" DOES NOT interfere, confuse, cause mis-read (or read), etc., etc., etc. of the TPMS sensors. *Though it is recommended that when initializing the TPMS sensors that the object wheels be more that 5' away from other not-to-be-initialized wheels.

BTW ... Personally have 3 sets of wheels (with OEM TPMS sensors installed) that are stored within 15' of the daily driven F-150 and there are not issues before and/or after swapping any of sets.
*NO

BTW ... IF after a swap the TPMS light were to come-on, it would do so within ~50-60miles.

BTW ... Would recommend that you do a LITTLE more reading on the topic of TPMS sensors before you provide supposition of how radio works. It's more that just turning the ON/OFF/volume-control/tuning dials.

BTW ... You use BTW WAY too much.
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gsxr1216

lets start this off with my winter tires are in my basement, magically in the exact same place they were last winter since thats where i store tires!

And my truck is parked in exact the same place its been parked since i bought it close to 2 years ago, right infront of my boat!

The ONLY thing that has changed over the past year is i put sensors in my summer wheels, nothing else.

YES i have driven far with my summer tires............. Put it like this last year with NO sensors in my summer tires i would get the message daily and like i said again in 15 minutes or so. here i am 2 months in no message EVER so far.

I know this doesnt make sense as i saw the same threads you saw and i said there no effing way the truck can pick up new sensors but some do for some reason as hard as it is to believe.

KR Kodi

iTrader: (1)

Thanks for confirming all the points I made!!


BTW - I'd like to take you up on your recommendation above to read some more info about the TPMS and sensors.


Could you provide me a source for how the TPMS does that automatic recognition of a new set of tire pressure sensors? That's one of the areas where I need to do a lot of learning.


TIA,


Bob


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Cover Dog

I ordered & then purchased in April of 2013 a 2013 F150 Lariat w/Max Tow & HD Payload. I have lowered the tire pressure from the recommended 55frt/60rear to 35 psi and the TPMS has never gone off. Does Ford only have one set of TPMS sensors that they use.

On other vehicles I own if the pressure drops about 7psi (35 to 28) you get the warning. I can't imagine running my pressure down to 28 psi before I would get a warning on tires that could be inflated to 80psi. I tow between 10-11,000lb fifth wheel.
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KR Kodi

iTrader: (1)

Here's a link to the NHSTA ruling with the requirements for the TPMS to give alerts when the pressure is 25% below the manufacturer's recommended cold inflation pressure:


http://www.nhtsa.gov/cars/rules/ruli...le.6.html#IV_1




In that document, scroll down slightly to the link to the "IV" section (or scroll all the way down to section IV), and you can read:


So....I don't know why your TPMS isn't giving you an alert. If the sticker on your door says Ford recommends 55/60 psi, then when the pressure is below 41.25/45 psi you should get the light and other alerts that you have low tire pressure.


You can read in that document linked above that there were many comments about the proposed rulemaking, and some of them said 20 minutes was too long, and 25% was too much of a loss of pressure (some responders said the limit should be 20%, and the Tire Industry Assoc said it should be 1 to 2 psi below recommended cold pressure!).

Abraham5G

I got new aftermarket wheels and tires installed with aftermarket tpms. I keep getting the "faulty tpms" message every time I start my truck. Will this method work with factory tpms only or also with aftermarket tpms?

gDMJoe

Ummmm ... Your points were refuted (not confirmed).

While RIF, finding reading material is also the fun. I already have my collection / reference-library so knock-yourself-out ... (as an example)Y'all be sure to report-back REAL soon.
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