R1200GS failed fuel pump controllers

R1200GS failed fuel pump controllers

See also: Fuel Pump Controller Bypass – there’s suggestions for workarounds / bypass leads below but this one is really neat.

Fuel pump controller failures, R1200GS and other BMW R1200 motorcycles.
In this article – what and where the fuel pump controller (regulator) is, possible ways to prevent failure and work-arounds that will get you back on the road in case of failure.

NOTE: Bypass leads are not intended / designed to replace a working FPC or as a permanent replacement for the FPC, the FPC is there for a purpose (to regulate the voltage supply to the fuel pump and so the speed it runs at and rate of fuel supply). The pypass lead is a something you carry in case of need that will get you home, to your destination in the event of a fuel pump controller failure or keep your bike running until you can source a new Fuel Pump Controller.

SURVEY – had a fuel pump controller fail? Post the details either contact me (AndyW) with the following details:

– When did it happen?
– Where were you?
– rider name
– bike details (model and year)
– remedy
– How many days work/holiday did you lose?
– Were there any incidental costs?

It’s not uncommon for the R1200GS (and other BMW R1200 series bikes) fuel pump controller (the finned alloy item under the vented black plastic cover on the top left side of the tank, photo below aka fuel pump regulator) to fail. This will either result in no fuel getting to the engine so the bike won’t start or worst case scenario, loss of power as you ride!

The culprit (item 7)…

There appears to be two causes for failure of the R1200GS / R1200GSA fuel pump controller (which may well apply to other BMW R1200 series motorcycles) both being an issue due to the poor design of the fuel tank pump housing module i.e. being recessed as it is causing water to collect around the fuel pump controller unit:
1) Ingress of water past the gasket / seal which the controller is seated on (item 12 in the diagram above) resulting in corrosion of the electrical connections / contacts beneath or possibly electrical shorting.
2) Corrosion of the fuel controllers finned alloy heatsick resulting in it overheating and failing.

A particularly badly corroded fuel pump controller heatsink

And on my bike, regularly checked, cleaned and ACF50 brushed over it

At last BMW have done something about this problem that has plagued so may R1200 GS owners redesigning the fuel tank for 2008 bikes so that water no longer collects as it did with 2004 to 2007 bikes. Water should drain from the more steeply inclined position…

Unfortunately the same is not true for 2008 R1200GSA R1200 GSA owners!

** See below for FPC bypass leads

What is the Fuel Pump Controller and what does the FPC do?

In simple terms it’s a voltage regulator that reduces the voltage supplied to the fuel pump itself to make it run at something like 50 to 80% capability. Quite why this should be necessary I don’t know (prelong the life of the pump? or reduce the heat output of the pump motor?) but I’d have thought a different pump design would negate the need??!!

UPDATE Apr2012 – it’s taken a long time but I finally have a detailed explanation of what the FPC does and why! Many thanks to Bob Wilson (Canada) for emailing me 😀

Here’s the actual function of the controller. It does not reduce the voltage to the pump, to extend pump life. In all BMW bikes that use a fuel rail that has no return line, the fuel rail has a pressure sensor. As the throttle is opened and closed, varying amounts of fuel are used, so a constant-speed pump would not keep the required constant fuel rail pressure.

In this system, the fuel rail pressure sensor sends a signal to the controller, which causes the controller to vary the average voltage it feeds to the pump to keep pressure constant. If the throttle is opened, more fuel is used, and in order to keep the fuel pressure constant, the controller increases the average voltage fed to the pump, which makes the pump speed up to maintain fuel pressure.
When the throttle is closed, the reverse occurs

I think I saw this information in the Bosch “bible” publication on FI and motor management systems. Anyway, to sum up, you may recall that there are two different types of inlet port injection systems……
First is the traditional electronic injection, where a positive displacement “roller cell” pump, pumps fuel into the fuel rail. The injectors take what they need, and the remainder is forced through a pressure regulator and back to the tank. The regulator is a simple mechanical one that provides a constant backpressure (about 40-45 psi usually) for the fuel rail. This type has been used since Bosch made its first electronic injection system (the D-Jetronic system originally used in the 1968 VW Squareback). It’s main advantage is that it’s simple! Its main disadvantage is that the fuel picks up heat as it is constantly circulated past the motor. This results in increased fuel tank temperatures and increased fuel evaporation. Recent strict EPA limits on this resulted in the so-called Non-Return system I described in my earlier comments.

As a way to solve fuel tank heating and subsequent increased evaporative emissions, the Non-Return system I described has become more common in the last few years. As I mentioned earlier, this consists of a variable speed, NON-positive displacement turbine pump, whose speed (and pressure) is electronically controlled by pressure sensor feedback in order to maintain constant fuel pressure, inder all conditions of fuel flow to the injectors.

Hope this is helpful!
Regards, Bob.

I don’t know for sure but as far as I’m aware the fuel pump controller seems to fail for one of two reasons, ingress of water past the seal the controller sits on causing problems with the electrical connections/contacts beneath and failure from overheating due to the controller’s alloy heatsink ‘furring’ up (corrosion / aluminium oxidation). Both relate to the poor situation/design of the tank with that recessed housing trapping/holding water!

UPDATE: 2007/2008 BMW now supply a revised fuel pump controller after recognising failures due to over heating and/or after a batch of faulty controllers being fitted to 2007/2008 bikes. Sadly a few riders are already reporting continued failures of the new fuel pump controller.


  • 2004, 2005, 2006 R1200GS models – check that the revised seal / ‘O’ ring (item 12 in the scematic above) has been installed, blue in colour
  • All bikes – check the condition of the seal / ‘O’ ring and apply a smear of silicone or other waterproof grease
  • All bikes – regularly check the condition of the fuel pump controller heat sink. keep it clean, remove any corrosion. The latest fuel pump controllers are powder coated – still worth keeping an eye on!
  • Apply a waterproof / anti corrosion coating e.g. ACF50 (use an old paint brush;-) Reapply from time to time e.g. after cleaning.
  • Mop out any water that has collected in the recess where the controller is situated after washing the bike (especially if the bike is not to be used for a while)
  • Some owners have sealed the ‘vents’ / slots in the black plastic cover and reportedly don’t have any issues as a result of doing this. Personally I have decided against doing this, I imagine BMW decided upon having the vents for good reason (cooling, allow evapouration of any damp?)

Failed fuel pump controller workaround 1 (Bypass power lead)

See also: BMW R1200 R1200GS Fuel Pump Controller Bypass

By ukGSer ‘Wapping’ 20Apr2008
Original ukGSer thread

Robin, of this parish (ukGSer Forum) was kind enough to give me the plug from the bottom of his written off fuel controller.

With this I was able to make a work around fix, enabling me to run the bike’s fuel pump without its controller, should my controller also fail.

I discovered that my controller was sitting in a deep puddle of murky water, dead flys and what our US cousins might call rocks. I call it small stones and grit. All in all, it’s not surprising water eventually gets into the controller unit, writing it off, leaving you stuck.

The controller is easy to remove, only two brass screws to undo.

Once the controller is out, you can see the plug and socket, sitting underneath.

I made a simple flying lead, using Robin’s donor plug. I had originally planned to power the plug from the switched auxiliary socket in the beak. Like most cunning plans this fell at the first. I discovered that the fuel pump must draw more than 5 amps, as the canbus simply switched off each time.

I made a second flying lead and ran it to the battery, via my Optimate’s flying lead. This gave me a suitably fused power supply. The only downside is that, as it is not switched via the ignition, the fuel pump runs continuously. This is not a problem as it is easy enough to simply disconnect the lead from the battery, no more difficult than plugging my Optimate in and out.

Whilst digging around for some connectors I found a spare Optimate battery flying lead. I will keep this to use should a friend’s (without an Optimate lead) controller break.

Having got the fuel pump spinning, I started the bike….Bingo!…..One bike running, without a fuel pump controller, without a problem. Certainly good enough to get me home…..or further.

A big “Thank you” to Robin for donating the plug

Failed fuel pump controller workaround 2 (Get you home/to a BMW Dealer)

The following is something Tim Cullis (ukGSer, GSclubUK & ADVRider) came up with when stranded in Morocco in May 2008. If you’re stuck with no breakdown recovery, no BMW Dealer within a reasonable distance and haven’t got a bypass lead (as above) you can follow Tim’s instructions to get up and running again.

By Tim Cullis May2008
I did a controller bypass to the existing wiring loom as shown below. OK, it’s not neat but this is something the dealer is going to have to sort out under warranty when I’m back in the UK!

The connector running into the TOP of controller has three wires. Bare the right-hand and middle ones (and try not to slash the other in half as I did). Make an ‘eye’ in each of the cables to accept the splice.

Cut the two cables with the terminator block off the BOTTOM of the duff controller and splice as follows: 
– the BLUE bottom cable into the BROWN top one
– the YELLOW bottom cable into the BLUE/GREEN top one.
Don’t cut the BLUE/RED wire as shown in the photo, that was a ‘slip up’!

Cover the connections well with insulating tape, plug the terminator block into its position and start engine!

BMW Fuel Pump Bypass Cable Installation Instructions Video

It is recommend to connect the accessory port directly to the battery and that it is fused. The stock accessory port has a 5 amp limit and the fuel pump can trip the canbus virtual fuse with it’s greater than 5 amp draw. To install the cable you need to carry a T-20 Torx socket in your tool kit.

Purchase BMW Motorcycle Fuel Pump Bypass Cable (external link)

Don’t fancy a DIY solution/can’t get the parts? – great value, premade bypass cable:
Purchase BMW Motorcycle Fuel Pump Bypass Cable (external link)

  • Julius says:

    Is this kind of fuel pump controler bypass,is suitable also to bmw s1000rr 2012 model?

  • Bernard says:

    I have bypassed the fuel controller on a bmw 1200gs 04 and the bike still won’t start. Any idea what it could be?

  • paul says:

    I have a 2010 R1200GSA, came out to return home from pub having ridden there perfectly ok, only to find it would not start, it turned over fine but not fireing up. i conclude there the fuel pump is not running as no noises when first turn the key.
    Would this be a symtom of this FPC fail;ure, or simply a defective fuel pump? my nearest BMW dealer is 30 odd miles away, i am or was a car technician so can do repairs myself but am not familiar with bmw bikes, although ive had many, they dont usually go wrong !

  • Simon R says:

    What is the polarity of the blue and yellow wires into the blue pump controller plug? Which is positive and negative. Quite an important piece of information when building an emergency lead.

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