View Full Version : Fun with TPMS sensors

July 30th, 2013, 02:31 PM
Here are two cracked TPMS sensors that were a casualty of rallycross ...


They have hairline cracks in them that were discovered after slow leaks continued in spite of replacing tires and wheels. Discount sold me some replacement aftermarket units that appear to be significantly more substantial (brass surrounded by rubber as opposed to thin-walled aluminum, maybe), but had difficulty programming them - several attempts during two trips were unsuccessful. They couldn't get Suzi into learn mode, and determined that was my problem. Finally I asked to see the instructions, and then, if I could perform the procedure myself, as I have a knack for making the computer-thingies talk. I was able to get the car into learn mode on the second attempt, with the Discount guy hitting RF reader at just the right time. I have seen other posts on the board of people having problems with TPMS sensor programming - I think it just takes patience and following the procedure exactly to get the car into learn mode, and two people, for sure ...

Here is a pic of the instructions I kept - hope it's readable (if not I can convert to text):

Hope this helps ...

July 30th, 2013, 02:59 PM
If you're rallycrossing wouldn't it be better if you had normal valve stems instead of the tpms? You'll keep braking them as they're not designed for high shock loads. You're probably bottoming out on the tire sidewall and braking them.

July 30th, 2013, 04:04 PM
Yep exactly, I replaced them because I like the functionality during normal operation ...

July 30th, 2013, 04:27 PM
Yep exactly, I replaced them because I like the functionality during normal operation ...

I understand you like them but they'll eventually become a burden if you keep on rallycrossing the car. The reason I don't have them is because of the sidewall movement I have during high speed corners. If I had them I'd probably brake them aswell.

July 30th, 2013, 07:21 PM
You got it - if/when I go to a dedicated set of wheels/tires, there will be no TPMS sensors in them ... in the meantime I think the aftermarket ones are much stronger - should've got a pic before they were installed. I was happy to defeat the learn mode thing and hope others can find a solution to this problem! :)

Still learning my way around here - I couldn't find a way to delete my double post - I'm assuming a Mod has to do that for me?

July 31st, 2013, 02:04 AM
When the instructions say to scan the sensor in steps 5 and 6, is this using a tool to scan the bar code or is it some other type of scan?

If I were to purchase a set of pre-owned wheels and tires would I have to demount the tires to scan the sensors and get the monitors working?
The SX4 is my first car with a TPMS and I want to know what I'm in for if I replace the wheels. (Mine's a 2010 so it has the steel wheels, I'm still looking for an inexpensive set of stock alloys with tires)

July 31st, 2013, 07:10 PM
In this case RF means Radio Frequency - TPMS sensors are little wireless transmitters - they have to be programmed to be able to transmit the air pressure to the car computer. The Discount guy told me a couple things: 1) that the tool was $2000 and 2) there were only two manufacturers of these sensors. In looking around a bit on Amazon after your question I can see little truth in those statements. The tools for programming vary significantly, from around $150 up to $1200, depending on what comes in the kit. The majority of sensors are either VDO or Schrader - the others may be re-branded, IDK ... I believe they installed these Schrader units:
But I paid more for retail, of course. I am assuming stealership would've been significantly more expensive. If you replace wheels, your existing units can be transferred to new the wheels, and programming should not be required. Mine transferred over just fine - the leaks were discovered after the new wheels as the sensors kept reporting low pressure. Once they are installed, it's all wireless, so the programming tool works while the tires are still mounted on the car.

July 31st, 2013, 08:33 PM
simple answer...switch wheels/tires for such events

August 3rd, 2013, 11:10 AM
has anyone here ever had any luck with programming the TPMS themselves with their own programmer?

Stinson Driver
August 7th, 2013, 08:27 PM
There was a post a year or three ago about folks buying programmers on Ebay and similar places and doing it themselves. If you are going to swap TPMS sensor equipped wheels twice a year (snow tires on seperate rims for instance) and want to have TPMS at all times, you would be money ahead to buy the programmer. If you only need sensors programmed now and then (when buying replacement sensors, for instance) you may as well just pay a good tire shop to program the new sensor after they install it.

When my sensors die (assuming it is an electronic death, not a leak such as the original poster had) I plan to just ignore the TPMS light and check my tire pressures periodically just as I have for the last 50 years of driving. Even with TPMS, I check my tire pressures routinely to keep them set just where they should be.