The problem about this speedometer kit (70900475) is the speedometer is designed to interpret the fuel level signal all on it's own, apart from the CAN BUS signal. Same as pre 2018 Softail speedometers.

The 2018 Street Bob speedometer we are trying to install is designed to display the fuel level as delivered ON the CAN BUS.

So we are gambling that because the 2019 Sportster ECM wiring diagram shows that it has a slot for "Fuel Level Signal" that by putting an actual fuel level signal to this pin, that the ECM will then put the fuel level signal ON the CAN BUS to be displayed by the Street Bob speedo.

 

@imh @007Duc ..so I checked my bike today (2020 XL883N) and, my speedo cable also has 5 wires instead of 6. I mean wtf!

Do you think if I bring this up to the dealership that my bike is not per the manual, that they will add the missing functionality? (I suspect them doing it since it practically does not affect the way the bike functions, but still, it's not per what the MC claims.

 

Are you looking at the speedo side of the connector or the main harness side of the connector? Only the main harness side should have six wires.

 

I checked the main side of the harness (one that goes to the ECM). It has 5 wires and one seal pin.

 

Well that doesn't sound promising.

 

I know. I'll be visiting the dealership on Friday to have a word with them on this and see if they can help me in anyway, since it looks like 2019 and up Sportsters are not 'to spec' (if you will).

 

@007Duc and @imh ..I was just browsing through the HD's Service Info Portal to take screenshot of the wiring harnesses of 2018 and 2020 models as evidence of comparison to put forward my point, when I checked the wiring diagrams for 2021 and 2022 models. Looks like MoCo updated the wiring diagrams of 2021 XL models on 6/17/22 to revert back to the 2018 schematic of wiring (they removed the extra wire added to the speedometer main harness that connects to the ECM for fuel level). Same for 2022. It looks like they realized they made a mistake and are correcting it. Doesn't sound like good news for us though.

 

Updates:
1. I had a facetime with the Guerrilla Cables team, they are committed to this project to help wherever they can. They tried a similar thing in a road glide (I think), with the same result no fuel information.
2. The team explained that the wire harness that they sent me has a jumper from port 4 to 5, as you guys can see on the attachment.
3. They told me the idea of connecting [200] 3 to [78] 12 will only turn off the gas light on the gauge, but will not provide fuel levels.
4. One test they told me I could do is pull a wire from [78] 12 to [20B] 5 so the ECM will receive the data from [20B] 4 that comes from [141B] 2. They tested that one on their bike (road glide) but it does not work either, we are curious to see what happens with Sportster.
5. They told me that the issue is probably software at the ECM level or at the Gauge level, they also said Harley's computer does not have options to change that, they are about to try another computer from a 3rd party that shows more options.
6. I did connect [[color=#222222]200] 3 to [78] 12 (opening the 12 on [78] is hell, no space to work at all) . The result was exactly what the Guerrilla Cables team told me, the gas alert light turned off, and nothing on fuel level.

Tomorrow I going to Harler to try to buy the terminal to connect [78] 12 to [20B] 5 and see what happens, but I'm not optimistic at all based on the Guerrilla Cables team report.

I'm pretty sure this ECM support this, but when Harley put the Sportster firmware they disable this port/function by default because the hardware is there the port exists. At my past Volkswagen card I have a scanner and software that allow me access assembly code, the community mapped a lot of functions there you edit the firmware at the hexadecimal level and get functions that were not even on the volks dealer software. I wish we have a similar thing for Harley.


Port 4 to 5 on Guerrilla's [39A] adapter.

 

I'm sure it is a software issue at the ECM. Because the speedometer we are using is designed to display what even information is put on the CAN BUS by the computers installed on the bike. Look at any 2018 and newer softail wiring, ie the Street Bob that we are using the speedometer from. The fuel level on the speedo is just a function of digital data on the CAN BUS that the ECM put there from the capacitive signal from the level sensor in the tank.

Also look at your wiring diagrams closely... 141A2 / 20B4 / 200B3 are all the same wire but are just at different points in the main harness. 141A2 basically becomes the source for capacitive signal when the level sensor is installed in the tank. But this in not digital information yet... With the resistor at 200B removed, 20B4 and 200B3 have the same analog signal on them that is coming off of 141A2. Connecting 20B4 to 20B5 and then 20B5 to 78B-1(12) is no different than connecting 200B3 to 78B-1(12). Just a MUCH MORE round about way of doing so.

I have spoken with Technoresearch about their Centurion Super Pro hardware designed to flash Harley Davidson blank ECMs. You can set the computer strategy apart from the VIN number and assign a VIN number to the ECM with this hardware. They told me that theoretically this was all possible to work, but it was not even close to a priority to them at the moment. Is the the third party computer that that Guerrilla Cables is using? I'm also curious as to what year of Bike (?Road Glide?) they tried this on.

 

I was thinking the same thing, that yellow wire interconnects as you explained. I only wonder why there is brown/white on the position [20B] 5 in the diagram, looking like planning for the future or something like that.

If we have a cheap reader I could try to dump the state with the signal and without it to see where in the firmware it was supposed to be configured. A lot of cars have entire communities that mapped a lot of functions, it is really unexpected that the Harley community does have something like this.
https://publicism.info/engineering/penetration/7.html