Faulty Fuel Level Strips

[tanneman]

First time post, so hello to everyone.

On pg 6 the proper neat solution has been posted.

[TXjames]

Originally Posted by tanneman

First time post, so hello to everyone.

On pg 6 the proper neat solution has been posted.

Sorry. I forgot to update over here. I will probably start a new thread with the solution written up more formally once I finish testing.

[ceasarfelix]

Originally Posted by TXjames

Sorry. I forgot to update over here. I will probably start a new thread with the solution written up more formally once I finish testing.

Someone could sell a lot of these things if they put together a simple unit for us novices that can be spliced in wire-to-wire

[drmajor]

I would like to get in on the new info when you have it ready...

Does the 2k and 1m resister just fool the bus that there is fuel and thus get rid of the FUEL warning?

[kk3an]

I replaced a fuel level sensor in a 2009 R1200GS last evening - bran new sensor & uncalibrated. Filled the tank to 5/8, and the gauge on the bike read 5/8. Filled the tank up full and the gauge read full. Fired up the bike and idled for 10 minutes, and the gauge remained reading full, as it should.

Prior to turning the key for the first time after the sensor install & with a bone dry tank, I cleared the computer (battery cables shorted).

The bike has 39,900 miles. For a short time prior to the sensor going bad, I had been transferring fuel - while riding - successfully from an auxiliary fuel cell. Early on after the sensor failure, I didn't know if doing this "on-the-fly" transferring would have been a contributing factor, but the more I think about it, I don't believe this would have any effect on the sensor itself.

If anyone has a different feeling about that, please let me know, but I think it's just a coincidence - mainly because the first few tank transfers went just fine.

Dan

[cjack]

Originally Posted by kk3an

I replaced a fuel level sensor in a 2009 R1200GS last evening - bran new sensor & uncalibrated. Filled the tank to 5/8, and the gauge on the bike read 5/8. Filled the tank up full and the gauge read full. Fired up the bike and idled for 10 minutes, and the gauge remained reading full, as it should.

Prior to turning the key for the first time after the sensor install & with a bone dry tank, I cleared the computer (battery cables shorted).

The bike has 39,900 miles. For a short time prior to the sensor going bad, I had been transferring fuel - while riding - successfully from an auxiliary fuel cell. Early on after the sensor failure, I didn't know if doing this "on-the-fly" transferring would have been a contributing factor, but the more I think about it, I don't believe this would have any effect on the sensor itself.

If anyone has a different feeling about that, please let me know, but I think it's just a coincidence - mainly because the first few tank transfers went just fine.

Dan

I take you are saying it doesnt need the recalibrating. I believe BMW agrees and they no longer require it.

[cjack]

Originally Posted by TXjames

Sorry. I forgot to update over here. I will probably start a new thread with the solution written up more formally once I finish testing.

The heater is about 35 ohms...so you are saying that the absence of heater current is acceptable?

[kk3an]

Originally Posted by cjack

I take you are saying it doesnt need the recalibrating. I believe BMW agrees and they no longer require it.

In just the two rough measurements I made (5/8 and full tank), there seems to be no calibrating needed - at least in my case.

Dan

[TXjames]

Originally Posted by drmajor

I would like to get in on the new info when you have it ready...

Does the 2k and 1m resister just fool the bus that there is fuel and thus get rid of the FUEL warning?

Yes. The 2k resistor replaces the fuel strip when its reading a full tank. The 1M resistor simply supplies the small bias voltage necessary to make the circuit work.

Originally Posted by cjack

The heater is about 35 ohms...so you are saying that the absence of heater current is acceptable?

No. The diagram shows the heater still connected. I have spoofed the heater using a similar 1W resistor but I have not completed testing. It is possible though.


If anyone knows where I can source the male side of the 4-pin connector please let me know! I could produce a plug-and-play solution that would require no electrical knowledge and provide it for the community.

[Bill the Bong]

I have had a replacement fuel strip on back order for a couple of weeks now. My dealer assumed that they are making changes to it. However, yesterday I got a call stating that BMW has developed new software to drive the fuel strips. My bike goes in next week. We'll see...

[TXjames]

Originally Posted by Bill the Bong

I have had a replacement fuel strip on back order for a couple of weeks now. My dealer assumed that they are making changes to it. However, yesterday I got a call stating that BMW has developed new software to drive the fuel strips. My bike goes in next week. We'll see...

Oooohhh, now THAT is news! Hopefully your dealer knows what they're talking about. Please keep us posted on the results.

[cjack]

Originally Posted by TXjames

Oooohhh, now THAT is news! Hopefully your dealer knows what they're talking about. Please keep us posted on the results.

I am guessing that the software is a "no calibrate needed".
As to improving the part, those of mine that I checked, (about 5 of them),had bad connections at the wire end of the think with no damage or changes to any part of the plastic strip. If USA gas affected the epoxy covering the wire to strip connections, then I guess BMW's blaming it on the gas may be valid, but remember that the key antenna also had a bad contact issue under the epoxy or filler, so maybe it was the USA air that caused that.
I feel that they just had poor design or QC on the contact part of the wires to the strip just like the key antenna. Hopefully the next batch will be more reliable although I just figure they sold out of the latest run.

[Dave RII]

Originally Posted by Bill the Bong

However, yesterday I got a call stating that BMW has developed new software to drive the fuel strips. My bike goes in next week.

If the fuel strip failure is due to a mechanical issue (broken contact), as mine were, then they can develop all the new software they want and the problem will continue.

[TXjames]

Originally Posted by Dave RII

If the fuel strip failure is due to a mechanical issue (broken contact), as mine were, then they can develop all the new software they want and the problem will continue.

This is true but I was under the impression that there are theories that the calibration method may be causing problems.

[Dave RII]

Originally Posted by TXjames

This is true but I was under the impression that there are theories that the calibration method may be causing problems.

I can see how a bad calibration method could cause a faulty reading on an otherwise good strip but not how it could make a good one go bad prematurely. I was present at the dealership when my first strip was replaced under warranty. Their replacement/calibration "procedure" went as follows:

1. Disconnect battery
2. Drain tank
3. Replace strip
4. Reassemble bike
5. Connect battery, turn ignition on, wait for system to boot, turn ignition off
6. Replace fuel in bike
7. Start bike
8. Hand me the keys and say "Have a good day"

Perhaps they would have done some additional calibrating if my gauge did not read correctly after the install.