Fuel Supply problems for R1200RT 2007

[MalA]

Hi All,

I know this appears to be going over old ground, but I have read so many posts on this topic that I have reached saturation point and got myself even more confused (if that possible).

My RT started to have intermittent cut out problems when hot (only for a few seconds at a time and would then run OK for a while, then repeat). Then failed completely. Will not start at all now.

1. So first thing I checked is fuel supply, and the fuel pump is not running at all (no typical whirr when turning on the ignition). Also, will not start the fuel pump when I use the "MotoScan" app in conjunction with my OBD interface.

2. Next thing, I pulled out the fuel pump/controller unit and supplied 12 volts direct to the pump. Pump itself works no problem.

3. The next obvious thing is that its the controller that has failed. I have read many cases of that on the forum. I checked it out, and apart from some minor corrosion which I rectified, it appeared OK. Its one of the black ones.

4. Before heading out and buying a new controller (as I am not aware of any way of testing this thing), I thought I would check the power being delivered to it. So the wires leading to the fuel pump are :blue (w/- red stripe), brown (earth), and blue (w/- green stripe). My understanding (please correct me if I am wrong) is that the blue with red stripe is from the ECU and "controls the speed" of the pump. The blue with the green stripe should be the "power" lead, and to my mind should be delivering 12V? Except mine only delivers about 0.3V. The blue with red stripe delivers about 3.5 V.

 

So having read numerous posts on this sort of thing, my questions are:

1. Will a fault in one of the many sensors on the motor cause the ECU to cut the "primary" voltage to the fuel pump unit?

2. If not, is it the ECU unit that's on the blink?

3. What else could it be????

 

Thanks for reading and being patient, I hope somebody can help.

Cheers

Mal

 

[dirtrider]

3 hours ago, MalA said:

Hi All,

I know this appears to be going over old ground, but I have read so many posts on this topic that I have reached saturation point and got myself even more confused (if that possible).

My RT started to have intermittent cut out problems when hot (only for a few seconds at a time and would then run OK for a while, then repeat). Then failed completely. Will not start at all now.

1. So first thing I checked is fuel supply, and the fuel pump is not running at all (no typical whirr when turning on the ignition). Also, will not start the fuel pump when I use the "MotoScan" app in conjunction with my OBD interface.

2. Next thing, I pulled out the fuel pump/controller unit and supplied 12 volts direct to the pump. Pump itself works no problem.

3. The next obvious thing is that its the controller that has failed. I have read many cases of that on the forum. I checked it out, and apart from some minor corrosion which I rectified, it appeared OK. Its one of the black ones.

4. Before heading out and buying a new controller (as I am not aware of any way of testing this thing), I thought I would check the power being delivered to it. So the wires leading to the fuel pump are :blue (w/- red stripe), brown (earth), and blue (w/- green stripe). My understanding (please correct me if I am wrong) is that the blue with red stripe is from the ECU and "controls the speed" of the pump. The blue with the green stripe should be the "power" lead, and to my mind should be delivering 12V? Except mine only delivers about 0.3V. The blue with red stripe delivers about 3.5 V.

 

So having read numerous posts on this sort of thing, my questions are:

1. Will a fault in one of the many sensors on the motor cause the ECU to cut the "primary" voltage to the fuel pump unit?

2. If not, is it the ECU unit that's on the blink?

3. What else could it be????

 

Thanks for reading and being patient, I hope somebody can help.

Cheers

Mal

 

 

Morning Mal

 

At what point in the key-on condition are your testing for fuel pump 12v?  You only get about 2 seconds of fuel pump run at key-on then it shuts the pump power down UNTIL actual engine cranking. 

 

What power state is the blue/green in during engine cranking?

 

What failure codes is your scanner showing now????? 

 

If you really don't have 12v power to the FPC for 2 seconds at key on, then full time 12v during engine cranking then first thing to check is the side switch discreet inputs.  The side stand switch is a 3 wire switch  so not only is a yes/no switch but also supplies a checksum to BMS-K. If the side stand switch inputs don't look right to the BMS-K then it won't start or run plus you can get engine cut-outs while riding. 

 

If you have 12v to the FPC during engine cranking then suspect a failed FPC.

 

Not sure what the "MotoScan" can test or look at as far as fuel pump or side stand switch, I have worked with 1200 riders before &  had problems with the "MotoScan" codes that they send me matching up to actual GS-911 derived codes. 

[MalA]

Hi DR

Thanks for taking the time to reply, its much appreciated.

 

My MotoScan tool does not have any reference to the side stand switch, so its pretty useless.

 

I follow what you said about the checksum to the BMS-K, and its possible impact on starting. I have also seen a youtube video where a GS rider cuts the lead to the side stand switch and shorts two wires to get the bike going, so I thought I would give it a try. So I pulled the connector to the side stand switch and shorted red to brown wires which my Haynes manual tells me is the up position for the side stand. No change in voltage to the Blue with green stripe wire going to the fuel pump when turning the key on. So I tried white to brown wires on the side stand switch. NADA. I even tried white to red. NADA.

 

Im not sure if that proves anything and if  I can safely rule out the side stand switch as the culprit.

 

I am monitoring the voltage of the Blue with green stripe wire from when I turn on the ignition key, so I should see any changes in the voltage that you mentioned at power on.

 

What power state is the blue/green in during engine cranking? About 9volts. I must admit I thought that would be about what to expect, rather than 12 volts, as there is something of a battery voltage drawdown at cranking?

 

So do you reckon I should replace the FPC as a first thing. That still does not explain why I don't get the fuel pump doing its thing for a few seconds at power on????

 

BTW, the error codes I am getting are 27B7, 27B8 and 27EB

 

Cheers

Mal

[dirtrider]

Morning Mal

 

My MotoScan tool does not have any reference to the side stand switch, so its pretty useless.-- That is not good news but it is what it is.

 

I follow what you said about the checksum to the BMS-K, and its possible impact on starting. I have also seen a youtube video where a GS rider cuts the lead to the side stand switch and shorts two wires to get the bike going, so I thought I would give it a try. So I pulled the connector to the side stand switch and shorted red to brown wires which my Haynes manual tells me is the up position for the side stand. No change in voltage to the Blue with green stripe wire going to the fuel pump when turning the key on. So I tried white to brown wires on the side stand switch. NADA. I even tried white to red. NADA.-- They will usually start if you jump the two outer wires, nothing to the center wire. 

 

Im not sure if that proves anything and if  I can safely rule out the side stand switch as the culprit. -- This won't totally rule out the side stand switch but possibly shows the problem is someplace else. (try jumping the outer two wires together with harness to switch still plugged in)

 

I am monitoring the voltage of the Blue with green stripe wire from when I turn on the ignition key, so I should see any changes in the voltage that you mentioned at power on.-- This is a good starting point.

 

What power state is the blue/green in during engine cranking? About 9volts. I must admit I thought that would be about what to expect, rather than 12 volts, as there is something of a battery voltage drawdown at cranking?-- 9 volts is a bit low but that should be enough pump voltage to start the engine. But 9 volts isn't enough for the ignition system or BMS-K to operate properly. Try measuring the battery voltage (at battery posts) during engine cranking, you want at least 10 volts, 10.5 is better, & 11v+  or higher is a LOT better. 

 

So do you reckon I should replace the FPC as a first thing. That still does not explain why I don't get the fuel pump doing its thing for a few seconds at power on????-- I see in your first post that you jumped 12v directly to the fuel pump & fuel pump  ran?  Did you try starting the engine with that 12v jumped to the fuel pump? If not then try that.  At some points it has sort of pointed to a bad FPC but at other time not exactly. If it will start & run with the fuel pump jumped to 12v then replace the FPC, if it still won't start with pump jumped to 12v  then your (current) problem is not the FPC. 

 

BTW, the error codes I am getting are 27B7, 27B8 and 27EB -- Those don't help much as I don't show those as valid engine malfunction codes  (I have seen this before in trying to diagnose using MotoScan derived codes).  

 

 

[MalA]

Hi DR

 

thanks yet again for the advice.

 

I thought I would take your advice on trying to start the engine with 12v jumped straight to the fuel pump. Bingo, started no problems, as I suspected it would.

 

So thinks I, why not try using the blue/green wire direct to the fuel pump (with the brown as earth)(bypassing the FPC). Bingo again, it runs no problem, and the strangest thing is I get the 2 second pump run at ignition on. Doesn't make sense as I was not detecting voltage on that wire. Add that to the things that confuse me. 

 

Anyway, it is obviously the FPC at fault and am getting that replaced ASAP. That will teach me to try and be too smart and get ahead of myself.

 

Cheers

Mal