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Discussion starter · #21 ·
Went back to the tire shop to see what they had to say, they indicated that although they could program many cars/tpms sensors, they couldn't do Fiats, MB's, Bmw's, and I would likely need to go to a dealer. He said the sensors MUST be paired to the individual car, via the OBD port. He also said that multiple sets of tires could be paired to a car and be successfully picked up, such as when running dedicated snow wheels. He claimed that if the sensors were pre-programmed to the car, then only driving the car with the new sensors and wheels for 10 minutes would be sufficient to read the sensors. Next stop.dealership. If that doesn't work, then likely bought bad sensors or with the wrong frequency.
 
I imagine the programming is needed in some but not most cases. I too had a sensor replaced and this was done at the tire shop simply by installing it, no programming required so it does seem to vary with circumstance. Buy 433MHz and do a lot of hoping or head for the dealer with $50 in hand I guess, maybe if you are in with the guys you can get around the charge.
 
Discussion starter · #23 ·
Dealer said pairing to the car was necessary, charged me $60. In the process, they found one sensor (purchased set of 4 on ebay for $40) was non responsive, so I had to replace that one with a new one from the parts dept. ($75 each!). Picked up the car, they said light should go out within 10 miles as the car had to "localize" the sensor info. Drove 35 miles home, light still on and no pressure data available. Call dealer, they say bring it back in, they mess with it and get it corrected. I go to pick up the car in an hour, hope all is indeed working as designed. I purchased a set of sensors for my friend from the same vendor, he hasn't mounted them yet, we are going to take them into the tech when I pick up the car and make sure the dealer's hand-held reader gets a reading on all four sensors before he has his mounted.
 
Thanks RND! Just had my TPMS sensors tested at the dealer and they passed….that means new 17" wheels and tires mounted tomorrow! RND…your wheel/tire setup looks fantastic…please share pics with the group. One good lookin' e.
 
Discussion starter · #25 ·
silversport just called me and said the identical sensors and wheels we got together have been mounted, and the TPMS worked right away with no programming, so I guess it is a hit and miss situation. Go figure....
 
silversport just called me and said the identical sensors and wheels we got together have been mounted, and the TPMS worked right away with no programming, so I guess it is a hit and miss situation. Go figure....
Lets try to figure this out. What model and year was the original post and what model/year was silversport? How about others experiences model year and result? Thu s can then be a guide to others since there is obviously some variable. Computers are not ever random either it works or it doesn't.

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Lets try to figure this out. What model and year was the original post and what model/year was silversport? How about others experiences model year and result? Thu s can then be a guide to others since there is obviously some variable. Computers are not ever random either it works or it doesn't.

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If it helps I had a single sensor replaced because the tire shop neglected to install it when changing tires. 2013 Abarth. Plugged it in and drove a bit and it worked without issue every since (several months).
 
Both RND and I have almost exactly the same car…500e's. America's Tire mounted the new rubber to the new wheels, installed the sensors and they worked like a charm. I cancelled my appointment with the Fiat dealer to have them "programmed". I did have the Fiat dealer check to see if all of the sensors were working and maybe there was something in that "check" that made them work correctly (but I doubt it). Dealer said that he could not activate the unmounted sensors because the car would have been "confused" (old sensors on the old wheels with new sensors in my bag). Whatever it was, the new sensors work perfectly and the new wheels and tires are very nice.
 
Hello everyone. I've read through this thread, and I'm wondering... If I change wheels and have the stock tires mounted on them, will I need to get new sensors? Or can they use the sensors that I already have? This is my first vehicle with the sensors, and I have no idea if you need to replace them when changing wheels.
 
You can move the sensors to new rims in most cases. The only thing that would prevent you from moving them is the new rim not being able to accept the sensors. This would be highly unusual if you buy a rim made for sensors as most newer rims are.
I have seen success using sensors in rims made back in the 1980s. As long as the inner shape accommodates them, and you can get a stem seal, you are good to go. Balancing non sensor rims using sensors can be a bit tricky, but it can be done

The tire has no bearing on the sensors. Stock or aftermarket tires make no difference. All tires can be used with or without sensors.
 
Thanks jabird. The wheels that I'm planning on getting are able to accept sensors. (I'm planning on getting the Monza wheels) I wasn't sure if you had to replace the sensors every time you changed wheels. It seems as soon as I bought a new car, everyone was warning me about the tire pressure sensors and what a pain they are. I haven't had any problems with them so far, but expected some trouble if I changed wheels or something. So, you answered my question... and it's good to know that the tire has no bearing on the sensors.
 
Discussion starter · #33 ·
Update: dealer ultimately replace on warranty my BCM (body control module) which is the unit that picks up the TPMS information that is sent via low-level radio frequency. Also, I ended up having to replace 3 of the 4 brand new sensors that I bought on Ebay, so buyer beware on getting them that way. Dealer price: $300/set, Ebay price: $40/set.
 
Update: dealer ultimately replace on warranty my BCM (body control module) which is the unit that picks up the TPMS information that is sent via low-level radio frequency. Also, I ended up having to replace 3 of the 4 brand new sensors that I bought on Ebay, so buyer beware on getting them that way. Dealer price: $300/set, Ebay price: $40/set.
Tire rack has them for $160 a set. At least with TR you can return them if they are defective.
 
I had this same problem and figured I'd post an update for other folks with a Fiat 500e that doesn't want to play nice with the TPMS sensors. I tried driving on the highway for a solid 15 minutes, no luck. I tried using a 125kHz tool to wake them up, also no luck. I also tried disconnecting the battery for a while, which also didn't work. At that point, I wanted to figure out what was going on definitively.

I ended up fixing this with MultiECUScan ($55), the yellow cable ($12), an EL-50448 ($14), and an RTL-SDR ($30). If you just need your tires fixed once, maybe it makes sense to go to a tire shop, but MultiECUScan and the yellow cable are useful in their own right. If you don't want to futz around with open source software, you can get a scan tool for around $120 on eBay, such as the Autel TS401. I happened to have all the hardware I needed sitting around from other projects, so I only needed a MultiECUScan license.

The first thing I needed to do was to get the sensor hex codes. I used the RTL-SDR with rtl_433 to get the hex ids for each tire. To do that, start the software, bring the antenna near the tire, and then use the EL-50448 to force the sensor to emit a reading. Mark down the id and repeat for all of the sensors. I had a set of Schrader sensors that I'd bought off eBay, and this software doesn't necessarily work with all sensors. Other brands might not work, which would require that you get a normal scan tool.

Once you've got these, use the yellow cable with MultiECUScan to program the sensors from the adjustments menu. You may need to add a leading zero on the front to get it to work correctly, since it takes 8 digits and you might only have 7. Also note that it requires it in hex format, so if you got the id from something that emits decimal form, you'll need to do a conversion.

Once you've programmed them, activate each sensor again with the EL-50448 to get the car to get a reading. At that point, the TPMS light should go off and the values should show up in the cluster. It beats paying a dealer, though it's still not clear to me when auto-learning works right or doesn't work right.

Side note: I originally tried manual programming with AlfaOBD, but it didn't work. The 2.1.4.0 software had an issue where you could set sensors, but only once and couldn't rewrite it. It seems like it's only half implemented. MultiECUScan did the trick.
 
I might have spoken a little soon. Turns out the sensor in the front right wheel looks to be a bit flaky. I got one solid drive in before the light came back on. While the sensor did respond yesterday, it's not responding to tools to wake up today.

Based on the behavior earlier today and the behavior now, I think the issue is that if one or more of the sensors doesn't send data back to the car at the expected interval, right after they've all been changed out, it treats it as a fault in the system and wont report anything. If you use AlfaOBD to get the status of the TPMS system, you can see working sensors will have reasonable pressure numbers and you'll see bad sensors or non-programmed sensors have 7000mbar as the pressure.

So sounds like I'm getting a new TPMS sensor and getting it replaced out. At least it's only one sensor that needs fixing.
 
Since someone else already necromancied the thread....

Any tips for sensors that are playing musical wheels? I had new tires/rims installed on my 2015 a few weeks ago, the 15" Monzas that are available from several vendors. Used my old sensors which were working fine.

Now it picks up all 4 pressures just fine, no error messages... except it can't seem to tell which wheel is which. It changes position of the front/rear/left/right wheels every time I drive the car, sometimes multiple times in one trip. It's been right a few times, but then it just changes again in a few minutes. I've got over 300 miles on the car since the new tires, it should have "learned" by now which wheel is which.
 
Since someone else already necromancied the thread....

Any tips for sensors that are playing musical wheels? I had new tires/rims installed on my 2015 a few weeks ago, the 15" Monzas that are available from several vendors. Used my old sensors which were working fine.

Now it picks up all 4 pressures just fine, no error messages... except it can't seem to tell which wheel is which. It changes position of the front/rear/left/right wheels every time I drive the car, sometimes multiple times in one trip. It's been right a few times, but then it just changes again in a few minutes. I've got over 300 miles on the car since the new tires, it should have "learned" by now which wheel is which.
You can manually tell the tire pressure module which tire is where using MultiECUScan. I did it with an OBDLink SX and the yellow cable. If they keep changing position, that's a bit weird. How do you know which is where?
 
You can manually tell the tire pressure module which tire is where using MultiECUScan. I did it with an OBDLink SX and the yellow cable. If they keep changing position, that's a bit weird. How do you know which is where?
Because the front tires are supposed have higher pressure than the rear. 2015 models show individual corner pressure. Not sure about older ones. So you can see when it thinks both left are high, both right are high, or one of each.
 
Was curious how this is supposed to work, so looked up the wiring diagram as well as the part. Looks like the part number is 68070888AI and the wiring diagram nor the physical image of it don't seem to indicate that it does anything except talk over CAN-B. Looks like the FCC ID for this thing is MRXMC34MA4.

108113


108114

108115


The troubleshooting guide lists these as possible causes:
  • Non-FCC compliant components
  • Aftermarket tires/wheels
  • Intermittent Tire Pressure Monitoring (TPM) sensor internal DTC
  • Tire Pressure Monitoring (TPM) sensor
  • Tire Pressure Monitoring (TPM) module
The non-FCC compliant component thing is kind of interesting. Are your sensors / tires / wheels all the same? My guess is that this thing is trying to figure out which sensor is where by using the power level of the received signal based upon that test setup.

If for some reason these vary per wheel, they might move around.
 
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