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Discussion Starter #1
I have been reading every post on fuel pumps and electrical issues on here and cannot find an answer to my problem.

Problem: When I turn key, fuel pump does not prime. Bike will fire but will not start. Put other hot connector on pump, it kicks on and runs, change back and still not running. It is not fuel related, battery related or plug related.

I have checked the fuse (#4) and the relay behind motronic and cannot tell if either one is damaged but they look clean. Check all wiring from fuel pump and see no damaged wires.

QUESTIONS: New performance chip was not set right, two front pins missed the pin holes. Tried to start with this config, would not start. Replaced with stock chip, will fire but not run. Is it possible that I damaged the motronic unit?

Any other tests, electrical, that I can try?

Really stumped on this one and have spent many hours working on it. Thanks for any input.
 

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I have been reading every post on fuel pumps and electrical issues on here and cannot find an answer to my problem.

Problem: When I turn key, fuel pump does not prime. Bike will fire but will not start. Put other hot connector on pump, it kicks on and runs, change back and still not running. It is not fuel related, battery related or plug related.

I have checked the fuse (#4) and the relay behind motronic and cannot tell if either one is damaged but they look clean. Check all wiring from fuel pump and see no damaged wires.

QUESTIONS: New performance chip was not set right, two front pins missed the pin holes. Tried to start with this config, would not start. Replaced with stock chip, will fire but not run. Is it possible that I damaged the motronic unit?

Any other tests, electrical, that I can try?

Really stumped on this one and have spent many hours working on it. Thanks for any input.
So, it ran fine up to the point where you swapped the chip, then you had that chip in with 2 pins not in the socket. And now with the original chip, it will not run?

The chip should only be a program loaded by the motronic so if you put power to the pump and it starts and runs, I would say you have the original chip in correctly.

It is possible that you damaged something in the motronic by swapping the chip. Did you practice proper static procedures when doing the swap? If not, then there is a chance of damage by static electricity. Not sure how to test for that other than swapping out the motronic or tracing the line back that runs the fuel pump relay. Not an easy task.

Someone else may have some ideas. I will be looking at the schematics in the Clymer to see if they shed any light.
 

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Discussion Starter #3
The stock chip was put in safely so I don't think the motronic is damaged but it will pricey to replace if that is it, unless someone has one lying around :grin:. Did put volt meter on fuse #4 and found no power coming to it but again, could be a bad read or attempt.



So, it ran fine up to the point where you swapped the chip, then you had that chip in with 2 pins not in the socket. And now with the original chip, it will not run?

The chip should only be a program loaded by the motronic so if you put power to the pump and it starts and runs, I would say you have the original chip in correctly.

It is possible that you damaged something in the motronic by swapping the chip. Did you practice proper static procedures when doing the swap? If not, then there is a chance of damage by static electricity. Not sure how to test for that other than swapping out the motronic or tracing the line back that runs the fuel pump relay. Not an easy task.

Someone else may have some ideas. I will be looking at the schematics in the Clymer to see if they shed any light.
 

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The stock chip was put in safely so I don't think the motronic is damaged but it will pricey to replace if that is it, unless someone has one lying around :grin:. Did put volt meter on fuse #4 and found no power coming to it but again, could be a bad read or attempt.
If I am looking at it correctly, and if the Clymer schematic is correct, it looks like pin 16 on the motronic is possibly the triger line for the fuel pump. If you don't get a +12 on that pin when you hit the key for the prime sequence, then I would say something in the Motronic is damaged as that looks to trigger the relay. If you do get the prime pulse, then you can look further down stream. Looks like a blue with red stripe wire.
 
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Discussion Starter #5
Thanks, I will check that in the morning.

If I am looking at it correctly, and if the Clymer schematic is correct, it looks like pin 16 on the motronic is possibly the triger line for the fuel pump. If you don't get a +12 on that pin when you hit the key for the prime sequence, then I would say something in the Motronic is damaged as that looks to trigger the relay. If you do get the prime pulse, then you can look further down stream. Looks like a blue with red stripe wire.
 

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Thanks, I will check that in the morning.
I think JZ also said this goes through the motronic relay and according to the schematic, it does. Fuse box 1 fuse 1 is a 4A fuse that might be involved through the multi function switch. Check that also.
 
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In reading JZ,s post on the other thread you dug up, it looks like that pin 16 is going to be an active circuit ground so the 12V should be there when the pump is not running and the motronic is not grounding the circuit. In that case, the 12V will not originate from the motronic.
 
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Problem: When I turn key, fuel pump does not prime. Bike will fire but will not start. Put other hot connector on pump, it kicks on and runs, change back and still not running. It is not fuel related, battery related or plug related.
So, by "kicks on & runs" I assume that you mean the fuel pump runs, and the engine never started. (the hot connector near the pump connector is known to run the pump backward).

If you think that you killed the ECU, You can get a new (used) one on Ebay for 50 bucks or less.
Just make sure it's from the same year or newer.
 

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Discussion Starter #9
No, the fuel pump nevers kicks on when plugged in correctly and ignition turned on. The next step, since the relays and fuses are all good, is to try a new motronic. I need to get my serial numbers and buy one. Thanks Rhawk2.

So, by "kicks on & runs" I assume that you mean the fuel pump runs, and the engine never started. (the hot connector near the pump connector is known to run the pump backward).

If you think that you killed the ECU, You can get a new (used) one on Ebay for 50 bucks or less.
Just make sure it's from the same year or newer.
 

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Discussion Starter #10
I will sell it for $3200, cash and carry or cash and tow. It's not like I will be able to ride it anytime soon after this foot injury.
 

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Fuse F4 is tied to always on 12V. So it should be hot all the time. Check both sides of the fuse to ground with a meter. If one side is hot and the other isn't then the fuse is blown.
 

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Could he swap wires to the plug to the accessory plug so that it runs the pump in the proper direction? Pump would run at key on.
 

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Could he swap wires to the plug to the accessory plug so that it runs the pump in the proper direction? Pump would run at key on.
He could do that as a test to see if the bike would then run but disabling safety features is not a good thing, ever.
 

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Do I replace the relay or go straight to the motronic? :crying:
First thing I would do is to pull F4 out as JZ said and measure again between both sides of the fuse plug and the battery negative to see if there is +12 on either side. I believe that comes directly from the battery and then feeds the ignition switch which I think then feeds the relays and a few other things.

Don't have my Clymer at work to reference the schematic at the moment to be sure of what I am saying. Trying to remember what I looked at after JZ said to check F4 again that it was always HOT.


alabrew made a suggestion of swapping the wires around in the Accessory plug ( always hot with key on ) and putting it on the fuel pump as the plug is the same only wired backwards so pump runs backwards. If you did this to see if the bike would actually start, I would not leave it like,that as a pump that runs even when the motor stops is a danger to continue ejecting fuel in the case of a leak even if the bike stops running.

Part of the interlocks that shut off the pump from certain conditions like the kill switch in the off position or no pulses from the Hall crank sensor.

If you don't have +12 on F4 then that is what you need to look at first. Let us know what you find there and get a good read this time :)
 
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Just tested Fuse 4 on the first block and have 0 volts going through it. Any thoughts?
Can you describe exactly how you measured and where? What you wrote makes no sense as voltage doesn't "move" and can't go through anything.
 
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Actually if the leads were on either side of the fuse and power is on that would indicate a good fuse. BUT, voltage needs to measured from at least one end to ground, to verify that voltage is present in the first place.
 

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Just wanted to make sure you are on the right fuse. If there is no 12v on either end of this fuse then you have a harness problem.
 

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Discussion Starter #20
Using a volt meter, placed black lead on - battery side and touched red lead to both sides of fuse 4. Each read showed continuity but no voltage. I tried with and without ignition on.

I am not an electrician by trade so I very well could be checking the fuse incorrectly.

Can you describe exactly how you measured and where? What you wrote makes no sense as voltage doesn't "move" and can't go through anything.
 
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