Keith Browning Posted November 28, 2019 Share Posted November 28, 2019 Do any Ford or Lincoln vehicles Auto sense the position of the TPMS wheel sensors? Quote Link to comment Share on other sites More sharing options...
lmorris Posted November 28, 2019 Share Posted November 28, 2019 There is nothing in the WSM to support that. I know it will auto update for different sensors if you don't train them, but it will randomly place those new sensors if all 4 are different. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted November 29, 2019 Author Share Posted November 29, 2019 I just perused the truck manuals and the F150 and also found nothing. I read some guy swears his F150 will relearn his sensors automatically when he rotates his tires. Quote Link to comment Share on other sites More sharing options...
8WA Sman Posted November 29, 2019 Share Posted November 29, 2019 Keith, Did he mention the year? Quote Link to comment Share on other sites More sharing options...
JoeR Posted November 30, 2019 Share Posted November 30, 2019 13 hours ago, Keith Browning said: I just perused the truck manuals and the F150 and also found nothing. I read some guy swears his F150 will relearn his sensors automatically when he rotates his tires. Any chance he just means he doesn't get a light or error when he rotates the tires? Joe Quote Link to comment Share on other sites More sharing options...
cbriggs Posted November 30, 2019 Share Posted November 30, 2019 Yeah there's no way. How could it possible figure out which one is where? Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted November 30, 2019 Author Share Posted November 30, 2019 11 hours ago, JoeR said: Any chance he just means he doesn't get a light or error when he rotates the tires? Joe He was quite sure that the truck knew which tire was where without retraining. I politely called bullshit after checking the WSM and making sure. Sometimes things get by me because I don't know the vehicle. I am pretty much all truck all the time and F150's are just under the class of trucks I work on. 5 hours ago, cbriggs said: Yeah there's no way. How could it possible figure out which one is where? That is what caught my attention knowing how the system works and the single receiver used. One of the Dodge techs in my shop thinks the newer Ram's do this... I have access to the Chrysler WSMs but they are atrocious. Quote Link to comment Share on other sites More sharing options...
jimmy57 Posted November 30, 2019 Share Posted November 30, 2019 Generally speaking, not sure about Ford, but there are high resolution sensors used that sense much smaller wheel incremental motion, and also direction, so ABS applies brakes if vehicle rolls with brake applied during engine off period for stop/start equipped vehicles. The tendency we have to ease up on brakes when we are stopped makes using the brake pedal position to know when to do this roll back prevention impossible without too many false engine starts. With high res sensors, steering sensor, and some turns the system can see the 4 sensors traveling at different speeds and determine the placement. The vehicles that have dropped pressure&temp sensors in the last few years do this same thing. You hit reset/calibrate after a rotate or replacement of tires and the responsible module (usually ABS) can adapt to worn tires with different circumference and then ID and know when that tire has signal change from deflation with sensitivity enough to do it on smaller circumference tires down to 8 psi. If there is a radio signal associated with the 4 determined wheel speeds then it is conceivable that the sensors can be learned with no intervention. The tire pressure being monitored allows knowledge of the circumference differences. I only know of cars using the no sensor iTPMS that use the same pressure on each position and no staggered tire setups. 1 Quote Link to comment Share on other sites More sharing options...
JoeR Posted December 1, 2019 Share Posted December 1, 2019 There's some Mopars out there that guess at the correct positions by using signal strength. They relearn the positions every time you drive the vehicle. If you stick with OEM wheels and sensors it works OK. Joe 1 Quote Link to comment Share on other sites More sharing options...
JoeR Posted December 1, 2019 Share Posted December 1, 2019 Here's a good example on how that system works. You're seeing a graph from an engineering tool. One of the things it can do is measure transmission rates and signal strength. Each color line is a different TPMS sensor. The height of the dots is a show of signal strength. The higher the dot, the stronger the signal. Notice that each one has a different average signal strength. Remember that the wheel is rolling when the sensor transmits. The sensor position might be closest to the antenna, or it might be on the opposite side of the wheel, so the signal strength varies when you're driving. Ignore the chart on the right that names the sensor position. It's not correct.. The antenna for the tool is on the driver's side dash. Maroon is Left Front. Green is Right Front. Blue is Left Rear. Red is Right Rear. 1 Quote Link to comment Share on other sites More sharing options...
8WA Sman Posted December 1, 2019 Share Posted December 1, 2019 Joe, If I understand your info, the sensor closest to the antenna has the highest RSSI (200) which would make the dBm closest to 0 (0.1) Quote Link to comment Share on other sites More sharing options...
JoeR Posted December 2, 2019 Share Posted December 2, 2019 You are correct. The higher the RSSI, the stronger the signal. If everything is working as designed, then the closest sensors will have the strongest signals. For a while there were some aftermarket sensors that had lower signal strength, and even lower rates of signal bursts. That could fool one of these systems into assigning incorrect sensor locations. I don't believe there are any of those around today though. Joe Quote Link to comment Share on other sites More sharing options...
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