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Dutchman 10-25-2004 01:52 AM

R1200GS Fuel Pump Failure
My recent trip to Germany & Holland was blighted by not one but two breakdowns apparently caused by the same thing, that the first dealer thought he had cured, but obviously hadn't.

If you remove the left hand fairing panel you see the fuel pump cover made from black plastic with slots in it.

After removing this cover, which is just a push fit, you'll see two electrical connectors & one quick fit fuel connector. The orange circle approximates the area which was filled with water when the first dealer removed the cover. The silver coloured component is the CanBus controller for the fuel pump.

Undoing two Torx screws enables the CanBus controller to be eased away from it's mounting. There is a rubber 'o' ring which seats between this component and the top of the fuel pump assembly.

When the blue push fit connector is released the CanBus contoller can be removed. The void below was also about half full of water, causing intermittent electrical shorts, which caused fuel pump failure, the symptom of which was just like running out of fuel, even though plenty was in the tank.

Here is the CanBus controller top & bottom view........the underneath is sealed with black silicone & the second dealer in Germany suggested that water ingress to this component was the definate cause of the breakdown rather that the now completely dried out electrical connections.

Replacing the CanBus controller has certainly cured the problem and I've now ridden about 500 problem free miles!!

Clearly there seems to be a design fault in a plastic cover, which is fairly obviously exposed to the weather when the bike is in motion, that then allows water ingress to an area containing three electrical connectors and where there is no drain for any water to immediately disperse.

For a motorcycle that is marketed as an all weather/all terrain vehicle this is quite simply unacceptable. The German dealer said he had replaced no fewer than five of these devices under similar circumstances and that he had, on each occasion, reported his findings back to BMW.

So that I am not further inconvenianced personally I shall devise a way of preventing the water ingress, but I have also written to BMW asking for an explanation.

Their reply will be published here.



Grizzly 10-25-2004 02:19 AM

Great story and pics Dutch. Explains clearly what was goin on with the failing of the fuel pump. Was talked about on the Dutch forum several times.

David_S 10-25-2004 03:43 AM

Thanks for the info and photos Dutch. I'll be inspecting mine some time soon just as a precaution.

ironbutt 10-25-2004 09:14 AM

R1200GS Fuel pump and Water

Thank you for the head's up. This sounds like a very important find.

Michael Kneebone

rideLD 10-25-2004 09:33 AM

Thanks for the pictures and all the info. I'm going to be checking mine also. I hope this was one of the early production bugs that got worked out before they started the main production run in late June like the hi-beam switch and the fuel gauge. Have there been any of these failures in Europe on bikes that were delivered after June 2004?

Colorado 10-25-2004 11:31 AM

Mee too
I have what I believe to be an early production R12GS. I was riding 2-up with a full tank when I had that same thing happen. Felt like it ran out of gas. The dealer first replaced the left side fuel pump, which has a fuel pressure regulator on it as well as the CanBus controller. But when the dealer took it out for a test ride, the same failure occurred. So, they replaced the right side pump which has another pressure regulator of some kind. Problem fixed (until it rains, apparently). Larry

marty hill 10-25-2004 11:54 AM

Hope they fix yours once and for all. That being said, I've ridden mine in 11 hours of very heavy rain without any problems. I've been on several other days that were a bit shorter but with lots of rain. Myl bike was built about 21 march which I think puts it on the tail end of the early bikes. All of the failures seem very random. Many of us are past 12k with no problems. Perhaps our turn is coming. :D

Poolside 10-25-2004 05:21 PM

Thanks for the great pictures Dutch. If the fuel pump controller was replaced, your bike should be in good shape.

That aluminum-finned device, though not part of the CANbus, is a controller. It is a controller/driver for the fuel pump. The controller initially operates the fuel pump at 100%, and then switches to an 80% duty cycle.

This new fuel pump controller on the 1200 is inserted into the bike's wiring EXACTLY where the fuel pump relay is on the 1100/1150 models. It is not part of the CANbus.

These new 80% duty cycle controllers were replaced at a high rate on the early chassis numbers. The first edition controllers are not designed very well. They overheat and die. But before they stop working, the excess heat warps the plastic portion of the case. The warped case ruins the shape of the o-ring groove causing it to leak.

Liquid isn't the issue here, it is the controllers themselves. Water is a poor conductor of low voltages. The the external electrical connections to the fuel pump on the 1100/1150 are unsealed. The alternators on both bikes are unsealed. Most every connector on most every motorcycle ever built is unsealed.

As an aside, there is an oblique benefit to mounting the controller outside of the fuel tank. It can be bypassed if you are stuck in the middle of BFE. Bypassing the controller lets the fuel pump run at 100% while you get home, but that is not an issue.

(the same 'bypassing' can be done with the 1100/1150 if the fuel pump relay fails)

According to BMW, the reduced duty cycle provides two things. One, it uses less current. And two, since the fuel system is a recirculating-type, operating the fuel pump at 80% circulates the fuel through the fuel filter less often. BMW claims the reduced fuel recirculation rate means the fuel filter does not require periodic maintenance. BMW claims it's a 'lifetime' filter.

- Jim


Some advances in fuel systems -

With current and recent designs, fuel circulates back to the tank after having been shunted at the fuel pressure regulator. The pump runs all the time, and fuel makes continuous round trips to and from the tank.

The newest automotive fuel systems are not the recirculating type. These new systems are similar to the 'dead end style' 'carburetor and mechanical fuel pump' systems of years ago. Similar to the older systems where the fuel was on a 'one way street' from the pump to the carburetor, these latest systems transport fuel only from the tank to the injectors. The fuel does not make a return trip to the tank.

The new systems do not recirculate fuel, and do not use a mechanical pressure regulator. Instead they use a sophisticated fuel pump controller and a brushless DC motor in the pump. The speed and timing of the brushless motor in the fuel pump is electronically controlled to maintain the system fuel pressure over all operating conditions, from idle to full-throttle.


David_S 10-28-2004 03:15 AM

I pulled my apart last night. I have a blue o-ring/seal verses the black one shown in the pictures. Hopefully the color indicates a change in the seal. Mine had no signs of water entry after 11,700 miles with a few solid days of rain and washing with a pressure washer.

NLS 10-28-2004 03:49 AM


Originally Posted by David_S
I pulled my apart last night. I have a blue o-ring/seal verses the black one shown in the pictures. Hopefully the color indicates a change in the seal. Mine had no signs of water entry after 11,700 miles with a few solid days of rain and washing with a pressure washer.

Seems you have an "updated" one - how do I know? (since people bubble about me not having a 12GS - sorry guys really sorry)
Well, this is one of the first things my local dealer noticed and told back to central... (I have a BMW GS after all, so we get to discuss things) it seemed that a sensor (he had one on the table and looked like this one on the picture) fails quite frequently (he has had changed at least three back then) on 12GS after... washing it (!) -we don't have much rain here. He also showed me the bike that it came from, in the general area of the tank (didn't care to pin point it for me), but seems this is the one. This insident happened mid-summer (three months ago). So seems BMW knows and PROBABLY (probably) has done something about it.

xover 05-22-2006 04:51 AM

this the same broken part from the bottom side, without the protection gum.

It has been replaced 4 (FOUR) times to my R1200GS , 2 times because of the wrong fuel level and 2 times because of BMW recall without explanation.
Now I have the explanation..

It is some 60 euro part that stops the bike.

Nd2Roam 05-22-2006 07:34 AM

unholy trinity
High beam switch
Fuel Pump
Fuel gauge

I hope that's the unholy trinity for early run R12GS's 'cause mines been in the shop for all three. I rode through a deluge on my way to have the switch fixed and on return I ran it out of gas (in the rain 20' short of the gas pump, thankfully). Soon after, the fuel pump died. I blamed myself for running it dry, I'm glad to finally know that wasn't the cause. The fuel gauge issue occurred while at the dealer for the 6k service. I hope it's adventure ready now. Still love this the bike though.

kdude 05-22-2006 07:52 AM

There was a recall notice sent out concerning this exact issue in Canada. Seems the oring was problem. I opened mine up on my 05 and did not see any water problem and yes I did some torrential rain riding.

xover 05-23-2006 01:08 PM


Originally Posted by ADVposer
High beam switch
Fuel Pump
Fuel gauge

I hope that's the unholy trinity for early run R12GS's 'cause mines been in the shop for all three. ...

It is not,
This is the lucky situation and mine one was not that..

2 times replaced gearbox

last part of te cardan transmission

2 driver saddles replaced

oil leaking from gearbox and cardan several times, sealing rings replaced.

Right now on 45000 KM ABS giwing random problems (not because of the sensor) after passing the check , just start engine and it is giving an error and SERVO pump working without tuching brake clutch. Seems on other forums all ABS system is to be replaced...

Had some valves problems (replaced part that pushing the valve)
appologize for my poor english

Ignition key replaced

Replaced the metallic cover (the big on the front) that protects the alternator belt

Have some problem on the left stand switch..

right heated clutch , replaced because burned

bearing replaced because broken (the one at the end of the Paralever before the transmission on the wheel)

So...for me the situation "Pump, Gauge , Switch" could be extremely fascinating :)


Nd2Roam 05-23-2006 08:41 PM

If mine goes that awry I will be back on a Japanese bike, fingers crossed mine will be reliable from now on.

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