Archive of BMW Motorrad Club Cape (2006 - 2019)

So you have had warning lights flashing in your face regarding faulty pressure sensors. I was told that this was due to the batteries in the sensors that are dead and will cost me R1600-00 a shot excl labour. Apparently these batteries only last for approx 4 years. By the way I have a '09 GS 1200.

Well here is a quick rundown on how to replace the batteries yourself. Please be advised that my quide is based on the GS 1200 sensor. I am not sure if there are other types that BMW has manufactured. It cost me a little labour,a steady hand and R10-00 for the battery.You will need the following hardware.

1. Carpet or modeling knife

2.Fine soldering iron

3.Thin wire found in coms cable or telkom cable. (preferbly the soft multistrand type)

4.Small thin flat copper plate  (not more than 2cm )found in an old torch or remote control.  This will act as a contact plate on the positive side of the new battery 

5. A CR2032 watch battery

6.A strong silicon substance such as sikaflex or marine silicon

First of all I assume that you have already removed the sensors from the rim.Be sure to mark the front and rear sensors so that you dont get confused when re installing them. This can be done by any good bike shop or tyre shop. Once they are removed you will notice that the one side of the sensor is covered in a rubber compound. This is were the battery is housed. About the size of a 5 sent piece. Carefully cut away from the centre of the sensor. The compound is about 2mm thick and you should see the battery. Carefully clean all the rubber compound around the battery. You will notice that the positive contact plate has been spot welded to the battery...stupid if you ask me. You will need to remove the contact plate where it is welded to the pc board. The contact point on the PC board is next to a small screw. Remove the contact plate and battery. Dont worry if the contact plate breaks from the battery. We cant use it in any case since since it cant be soldered on. The negative contact plate situated underneath the battery must stay there. Now solder the wire to the contact point on the PC board and the other end to the small copper plate . Fit the new battery making sure that the positive side faces upwards. The trick now is to ensure that the copper plate makes contact with the battery at all times. The way I did it was to take a 5 sent piece and place it on top of the copper plate almost like a sandwich and then bind the lot with a thin piece of binding or copper wire by wrapping it around the body of the sensor so that the copper plate makes perfect contact with the battery. Now use your silicon and spread it evenly over the battery and rest of the exposed PC board. Make sure not to get silicon into the 2 small holes in the sensor housing as I suppose this could affect the operation. After the silicon has dried properly remove the piece of tie wire holding the battery and contact plate. The 5 cent piece stays there. 

And thats it...if you shake the sensor you will hear a small ball bearing rolling around inside..this is the switch that turns the sensor on when the bike is in motion over 30km/h and not something you forgot inside.

This might not sound like a very pro job but it works and beats the hell out of paying R4000 for new ones and they were busted anyway so what have you got to loose. One word of advise is that you must make sure the sensors is allighned perfectly with the rim and be careful when removing or fixing the sensors to the rim since the steel part that houses the valve breaks very easy. Once installed you can switch on and the tyre sensors should give a default reading of "---"  Run the bike over 30Km/h and you should get your pressure readings back.

Good luck..if you feel this is too much you are more than welcome to contact me and I will do them for you.