Hey everyone.

I recently upgraded from an old Sporty to something "more reliable". This past month I picked up a 2011 Fatboy Lo with 5,000 miles.

After getting the bike I noticed a red error code light after only a few days. The error code was that the speedo and ECM were seeing high voltage. After doing some trouble shooting I determined that the voltage regulator was at fault. I purchased a new regulator and the problem went away and I was able to ride for a week with no issues.

On the way back from work today I noticed that my bike would backfire in 5th and 6th gear if it surpassed 2300 RPM. After taking it for another test drive things went down hill.

I noticed that my 5th and 6th gear sputter was still present. While sputtering the speedometer needle would go crazy. Next as i drove the fuel light flashed on and the bike stalled out. I pulled over and let it sit for a minute. As I turned my blinker on to get back onto the road, I noticed that the left blinker light did not turn on on the console (both blinkers themselves worked fine). The rest of the indicator lights worked perfect. Finally as I was gimping home the bike kept stalling out on me.

In summary:

- The bike sputtered above 2300 RPM in 5th and 6th gear
- The speedo needle would go haywire
- The left blinker indicator light doesnt work on the console
- The bikes now dies at idle
- The ECM stores the code P1632 (learned odometer mileage)

So far I have tested the battery. Reads 12.7V when off, and idles at about 13.90V. I plan to try to put the old voltage regulator on to see if maybe I received a faulty unit.

Any ideas? I'm at a loss...

 

Update: Installed the old voltage regulator, still having the same issues.

 

Took the gas tank off, did not see any pinched fuel or vent lines.

Anyone got any other ideas?

 

Check the connections at the ignition switch.

 

I took at look at the ignition switch then I was pulling the tank, and everything seemed to check out.

Would a faulty ECM or BCM be a likely culprit for these symptoms? The engine (spark), blown out indicator light, and speedo would all receive signal from the BCM correct?

 

The vehicle speed sensor, turn signal security module also could contribute. Speed sensor is relatively easy to clean and check. Bike isn't that old, this seems odd. With the code that was thrown, the vss is first thing I'd check.

 

I'll give cleaning the VSS a shot tomorrow after work. That could be a likely cause as it could prevent the ECM and odometer from synching up.

I agree that this problem is odd at such low mileage and age. This past/first month of owning this bike has been nothing but a headache...

 

So I pulled the VSS after work today (was a bit cramped but I managed to do it without pulling off the rear wheel). It looks very clean, only had one small metal shaving on the end of it.

I did notice two small pits, 180 degrees apart from one another. Not sure if this would have any impact on performance, or if they're normal due to the manufacturing process.

I also removed the BCM and ECM so that I can apply some dielectric grease when I reassemble. I plan to do the same to the VSS sensor.

So digging into this I could not find any shorted wires, and the VSS looked very clean. Any other ideas?

 

Here are the images of the "pits" in the VSS. Is this normal? Would this be enough to cause an issue?

 

Looks ok to me. Do you have a tuner on the bike? If not, do you have access to a known good ECM? To swap in and see if this is the problem.