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Discussion Starter #1
Hello everyone,
I have searched but I can not find where anyone has mentioned that their ECM needed an update after the Fuel Gauge Sending Unit was replace. When I ordered the new unit the parts guy mentioned that the bike would need an update but couldn't answer any of my questions. Then when I went to pick the part up I got a lot of shoulder shrugs and some "I don't know about that" replies. So I have a 2007 VRSCDX and I have a new sending unit but I don't know if I should just install this at home and risk issues. Any help is appreciated.
 

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As I understand it these units, like the one they replaced are sonar based, they point down and read fuel level. The earlier ones were inaccurate so HD upgraded it by adding a float that the beam would read more accurately. The difference in fuel level is nominal but I did hear that they wrote an upgrade adjustment. Whether it makes much difference or not I can't say. It will still work just might not be as correct.
 

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Discussion Starter #3
As I understand it these units, like the one they replaced are sonar based, they point down and read fuel level. The earlier ones were inaccurate so HD upgraded it by adding a float that the beam would read more accurately. The difference in fuel level is nominal but I did hear that they wrote an upgrade adjustment. Whether it makes much difference or not I can't say. It will still work just might not be as correct.
Thank you!
 

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Hello everyone,
I have searched but I can not find where anyone has mentioned that their ECM needed an update after the Fuel Gauge Sending Unit was replace. When I ordered the new unit the parts guy mentioned that the bike would need an update but couldn't answer any of my questions. Then when I went to pick the part up I got a lot of shoulder shrugs and some "I don't know about that" replies. So I have a 2007 VRSCDX and I have a new sending unit but I don't know if I should just install this at home and risk issues. Any help is appreciated.
THE ELECTICAL SHOP MANUAL SHOULD HAVE AN ANSWER FOR THAT QUESTION-- IT COVERS ALOT OF SHIT ON WHAT NEEDS TO BE DONE WHEN CHANGING SENSORS--I AM WORKING ON MY V-RODS ELECTRICAL SYSTEM --I BOUGHT A TUNER THAT WILL DO EVERYTHING THAT THE ONE HARLEY USES IN THEIR SHOPS --TECHNORESEARCH--IS THE COMPANY
 

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THE QUESTION WAS ALREADY ANSWERED 10 DAYS AGO
 

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Discussion Starter #9
THE ELECTICAL SHOP MANUAL SHOULD HAVE AN ANSWER FOR THAT QUESTION-- IT COVERS ALOT OF SHIT ON WHAT NEEDS TO BE DONE WHEN CHANGING SENSORS--I AM WORKING ON MY V-RODS ELECTRICAL SYSTEM --I BOUGHT A TUNER THAT WILL DO EVERYTHING THAT THE ONE HARLEY USES IN THEIR SHOPS --TECHNORESEARCH--IS THE COMPANY
Thank you. I'll check them out.
 

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That electrical diagnostic manual cost about ioo usd --you can find one on line in a pdf format for under 20 bucks --it is the same manual as the printed one word for word
 

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Thank you. I got the bike back together and the gauge reads full and it's at approximately 3/4 of a tank. So I guess I will call the dealer tomorrow.
the electrical manual doesnt say anything about needing any programing ---the schematic just shows the fuel guage wiring and it doesnt run thru ecm it is a stand alone system --i took this straight from the manual just now
 

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Hello everyone,
I have searched but I can not find where anyone has mentioned that their ECM needed an update after the Fuel Gauge Sending Unit was replace. When I ordered the new unit the parts guy mentioned that the bike would need an update but couldn't answer any of my questions. Then when I went to pick the part up I got a lot of shoulder shrugs and some "I don't know about that" replies. So I have a 2007 VRSCDX and I have a new sending unit but I don't know if I should just install this at home and risk issues. Any help is appreciated.
the fuel system circuit is a stand along system and a plug and play repair-i see nothing about anything about the fuel system needing to be programed
\
 

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I think you need to find some shade and get out of the desert heat.
Once again it was a TSB. TSB's are not in any manual. It is a update from the MOCO to address a problem mid production. As stated before there is a calibration download for the gauge on the first 2 years with the faulty sensor.
There was a early TSB M-1249 that updated the sender and reflash for 07-08 models. 09 and up did not need the recalibration flash

Fuel Gauge Service Bulletin M-1249
And as far as the fuel gauge being a stand alone system, that is false. The fuel range function calculates off of the fuel level. The ECU calculates input from fuel level, vehicle speed, engine rpm and injector fuel flow to calculate DTE Mileage remaining.
 

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I believe the programming is to take the differences from a non float to float since the reading is taken from the top of the fuel with no float but on the top of the float with the latest version on the right. Basically slightly different readings between float top and no float top of actual fuel level.
Ron
 

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