Author Topic: TPMS Issue  (Read 244 times)

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Offlinee7navy1999

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    TPMS Issue
    « on: 2018-08-29 15:51:52 »

    Good Day All.  2012 GTL ...My rear tire TPMS seems to be stuck on 35PSI.  I know for certain there is 40-42 PSI in the tire as I used 3 tire gauges to verify.  Even when I put in 42-44PSI the TMPS only reports 35PSI after 10 minutes on the road.  It does raise to 37PSI after 30 minutes on the highway at 80-90MPH.  FRont tire is dead on PSI+/- 1 psi.


    Question: Is this a TPMS battery Issue? Calibration Issue? Can the TPMS be recalibrated with my gs911?  I did find an interesting blog where the owner changed his TPMS battery but instead of using the original sketchy battery connections with hot glue he used a CR2032 battery holder with wires and soldered then in place to the OEM battery tabs.  On ebay I found a CR2032 batter in-cased in shrink wrap and has two wires for easy soldering for $15 for 10-each minimum.  Here is the link: https://www.ebay.com/itm/3V-CR2032-Lithium-Coin-Battery-with-2-Inch-Leads-10-pcs/112197460603?hash=item1a1f7d627b:g:cTUAAOSwHMJYIPkG

    Offlinee7navy1999

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      Re: TPMS Issue
      « Reply #1 on: 2018-08-29 18:52:36 »
      I phoned my local BMW dealer: they said they have been having issue with TPMS on all the BMW's.  The +/- 7PSI band is normal.  They do have some luck draining all the air out of a tire and refilling it.  Sometimes to zeros the TPMS where it reads normal again.  I will try that this week or at my next tire change in about 1 month.  If the TPMS is replace they charge $78usd to hook up their TMPS learn tool but you have to provide the new TPMS serial ID number.  The relearn tool is about $350 and you can use it for cloning as well

      Offlinee7navy1999

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        Re: TPMS Issue
        « Reply #2 on: 2018-08-30 17:08:22 »
        Found this on a different blog.  I will try and let ya all know how it does.  https://www.hexcode.co.za/products/gs-911/procedures/rdc

        Offlinee7navy1999

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          Re: TPMS Issue
          « Reply #3 on: 2018-09-09 23:20:03 »
          issue: My rear TMPS K1600 2012 is reading 7-8psi low.  Actual tire pressure is 40-41psi, TMS reads 32-33psi. I suspect the Rear TPMS is bad.  I tried to do the rapid decompression of the rear tire a few times.  The Canbus responds as designed with a red triangle and the engine going into "LIMP" mode so I know the computer and TPMS are talking.  For some reason the Rear TPMS became un-calibrated.  I suspect it is toasted.  My BMW dealer said they have issues with many of the TPMS sensors doing this.  They told me to try the rapid decompression a  few times and that sometimes wakes the TPMS up and calibrates it.  A new BMW OEM TPMS is $220usd.  Another kidney donation! 

          This is what I will try as my next step to troubleshoot the 7-8psi discrepancy in my rear k160 TPMS.  1. I purchased a : https://www.amazon.com/gp/product/B074MWMNL5/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1  EL-50448 TPMS tool for $16 from Amazon.  2. I also purchased two new CR2032 batteries with wires : https://www.amazon.com/gp/product/B00XYSW3R8/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1  about $12 total. 3. I purchased two new TPMS sensors from ....YES China:  https://www.ebay.com/itm/8532732-Tire-Pressure-Monitoring-Sensor-New-For-Fits-BMW-Genuine-High-Quality/253672435640?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649  8532732 Tire Pressure Monitoring Sensor New For Fits BMW Genuine High Quality  $25 each.  free freight

          I read on a previous blog that these new TPMS from China work on most BMW's 2012 to current year but that the battery they come with may be old...thus the new CR2032 battery with wires.  You can not solder the lithium battery as they get hot and it ruins them.  I do not like the idea of using a holder or just the existing metal prongs with hot glue to hold the battery in place.  Regular riding it would be find but once you hit some speed bumps or potholes at 80mph i think the battery would dislodge.  I plan to remove the glue in the new Chinese TPMS , TPMS, dig out the old battery and solder in new batteries using the wires directly to the terminals.  The next battery change in 3-5 years would be a really fast operation.  Since the CR2032 has a wire I will just epoxy the new battery an inch away from the new TPMS.  During a future changeout I just break the glue and put in a new battery with epoxy...should take about 5 minutes each. 

          Why the EL-50448: The chinese TPMS do not seem to have a serial number on them.  This would read the TPMS during wake up mode and give the serial number for my GS911 input.  https://www.hexcode.co.za/products/gs-911/procedures/rdc  The EL-50448 will also be able to test the Chinese battery and I may not even need to use the new wired CR2032 batteries this time around.  I will keep ya all posted

          Offlinee7navy1999

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            Re: TPMS Issue
            « Reply #4 on: 2018-09-09 23:21:06 »
            UPDATE Sept: I opened up the rear tired by just breaking one side of the bead.  Form there I was able to step on the tire and crush it done to make for plenty of room to remove the TPMS.  The old battery measured 2.67 DCV, The new battery measured 3.47 volts.  I followed the "de-glue" procedure mentioned earlier by a poster on this same link.  (took about 30 minutes) I soldered in the Black wire to negative (bottom tab) and red to positive (upper tab).  I did NOT fill in the cavity of the old TPMS with anything...just left it open.  Maybe I should have to help keep moisture out? Anyways I have to put on a new rear tire in about 1000 more miles so can do it then. The existing BMW TPMS terminal clips are extremely sturdy and solder very well.  The next battery change out will be very simple...maybe a 5 minute job at most. The new battery has two 2" long leads (+red/black-).  With ignition key on and tire not mounted but nearby the bike: I filled the tire with 40psi, proceeded with a rapid depressurization which "woke-up" the rear TPMS sensor then proceeded to fill up to 40 PSI.  The display ready 44PSI, Tire read 40PSI.  Better then the 8PSI difference I originally had but still not perfect.  Good enough?  I will run this pressure for a few weeks and see if it calibrates over time.  If it does not I will install the Chinese TPMS once it arrives next month during my tire change-out.  One odd issue: the CR2032 is thinner then the OEM battery that is labeled 11Y8Ou,  same voltage