2018 GSA TPMS - 4 sensors or 2?

[NoiZboy]

I have a 2018 GSA, and am running the current GS-911 & software.  I purchased a second set of wheels with additional TPMS sensors, and used the GS-911 to program the bike for the new sensors.  I recently put the original wheels back on (for summer off-road riding!), and the bike no longer "sees" the original sensors.

Looking on the Hexcode website, they show a version of the GS-911 software clearly indicating (and allowing a user to select for programming) any of four sensors on a GSA:  http://www.hexcode.co.za/products/gs-911/procedures/rdc

However, my setup shows a different screen layout and no ability to specify which "slot" (other than front/rear) a given sensor will fill. 

When I programmed the additional sensors, I thought maybe the new ones would automatically be assigned to "slots" three and four.  However, I recently put the original wheels back on and after several rides I'm still getting TPMS errors/no tire found.  It seems unlikely the TPMS sensor batteries are dead, as they are less than 1 year old and worked fine back in the fall.  Instead, it seems the bike no longer recognizes those sensors, or at least isn't using them/is looking for the other wheels.

I then tried reprogramming the bike for the original wheel's sensors, but couldn't seem to get either wheel to register in "Learn" mode within the GS-911 software.  Since the software indicates a bike will not "relearn" a known sensor, I'm not certain whether the bike still "knows" but is just not tracking the original sensors, or if I just couldn't wake up the sensor with my VT-15.

Does this mean the newer GSAs only accommodate two sensors, or is there something else I need to do to get the original wheels' sensors to be recognized/tracked by the bike during riding?  Is there some other reason my GS-911 software screen looks so different from the one on the Hexcode website?

Thanks!

[Jughead]

As far as I know the liquid cooled models only accommodate 1 set of sensors.  The pre 2013 models accommodated Set A (Front and Rear) and Set B (Front and Rear).

In your case, you would need to wake the sensor up and place it in learning mode before the system will pick it up.  Alternatively, if you can find someone with a wake-up tool, they will be able to provide you with the sensor IDs, which you can then manually enter.

It would be a good idea to write the current ID numbers in the back of your service book for future reference.

[NoiZboy]

Well, that's lame.  . Oh well.  Not a big deal but good to know I wasn't missing something.  Thanks!

[Honolulu]

NoiZboy, what does your dealer say?  Your bike is still quite new, so you would have been to them recently unless you got the bike used.

Anecdote:  When one is cruising around the universe and lands on a strange planet, one asks the natives if there's any intelligent life there.  Any answer is significant. 

Explaining, because words can be misinterpreted: simple questions can be asked of your dealer, and anything from silence to a complete technical exposition may have some value.  You paid for a premium bike, the service should be similar. 

[NoiZboy]

So, I did check with my dealer (Bob's BMW in MD - great dealership!) on a related point.  They confirmed there's only capacity for two sensors, and also confirmed there's no limit to the number of times the system can be reprogrammed to go back and forth between the tires.  Once I have the sensor ID's for all four tires written down, it will be an easy matter to switch them back and forth ... or I can just ride & ignore the RDC warnings.  Will probably do some of both depending on how long I expect to be using a certain set of wheels.

[Honolulu]

Excellent response, brings closure to the subject and conveys it for all to realize.

So hard to find info on the operating characteristics of these bikes, any little bit should be published for all to see.