My brother just called from on the road. His 2021 Street Glide Special is running fine but when NOT in diagnostic mode is showing codes in the odometer window. In addition to mileage, miles remaining (reserve), trip A and trip B, a RF40, RF39, and RF41 codes are showing up. After calling me, he did go into diagnostic mode and tried to clear but they wouldn't clear. On the web I was able to find that the RF40 code seems to indicate a communication problem between the ECM and the BCM.

He had a yellow light come on while riding so he stopped to investigate. He couldn't remember the exact check code procedure but remembered that the odometer on the switch box was involved and that's when he saw the RF codes. When he called, I reminded him of the procedure.

Anyone have experience with anything like this?

 

Once in diagnostic mode he can delete the codes if they are historical. If they are current they wont delete and the check engine light will stay on.

 

If he has RDRS (TPMS), those numbers look like tire pressure readings, typically FR (front) and RR (rear) and there's also a R for range left. These are numbers that show when you cycle through the ODO gauge. Those number values are in the tire pressure range.

Just a thought if he's not familiar.

 

I suspect your brother was seeing the TPMS message.

Was it RF 40, or FR 40?

 

I'm sure that's exactly what it is. Don't I feel stupid but my 2018 does not have TPMS. He bought the bike a couple years back when it was 2 years old with only 300 miles on it and it had no owner's manual with it and chose to not follow my advice to get one. Maybe this will encourage him to get one. I assumed that the TPMS readings appeared in a screen within the GTS system and had no idea they showed up in the odometer screen. My 18 only had the GT system. Thanks very much.