Interesting M8 thing.
 

Not sure if anyone else noticed but if you cut the ignition off while coasting down hill, the engine stops but everything else says on until the bike stops moving.. I suspect that TCs with a BCM do this also but haven't tried one. My driveway slopes down to the garage and I first notice the that headlight stays on as I shut the motor off once I start down. Notice the light on the garage door and it went out when I stopped. Noticed the instruments stay on also.. It's an RK so can say what the a radio does..

Im glad you explained how you came to find this out.

Mine does the same thing. And yes the radio still plays. 17 FLHTKSE

Ditto!

Go ahead and cut off the ignition while coasting down hill and loading up the cylinders with unburnt fuel. It's your bike. Worse things could happen but not by much!

On these fuel injected bikes, if the ignition is off, how is fuel getting into the cylinders?

Especially if you pull the clutch in while coasting ..............

Easy explanation, every FL series Harley since 2014 has a CAN BUS electrical system on it, which is not like your traditional fuse/circuit/wire arrangement you might be used to. The electrical system will stay on for appx 30 seconds after ignition cut-off, that's pretty typical for all CAN BUS systems which you see in modern cars as well. You also have to be more careful if adding electrics in a CAN BUS system (such as LED turn signals, driving lamps, air horns, etc) as the old splice/tap method can set a system fault. For light reading on this kind of electrical system go here:

https://sewelldirect.com/learning-ce...bus-technology

Besides it being EFI, I found this special gear between 1st and 2nd that allows you to coast with the motor not running. :D

You know, when rain comes from the south, my right knee bothers me. when it comes from the southeast, my left knee bothers me. yeah that info is about as relevant as this thread. LOL

If you read the CAN bus spec you'll find that it has nothing to do with power control. It's simply a definition of communications system that allows different parts of a vehicle to communicate with other parts of the vehicle. It just happens that the BCM was implemented about the same time as CAN. BCM is the power controller which adds features like wire load monitoring..

One thing to note is that all of the devices that use the CAN but have power even after the ignition is shut off. ABS, both handlebar switches, Speedo, Secutity, and ECM, all have power directly from the battery (Through a fuse). It's one of the reasons it's advisable to pull the main fuse when working on the wiring. The buss at idle does not draw any power. The CAN devices go into a lower power mode while the motorcycle ignition is off. Devices draw in the micro amps.

When something fails you can always take the bike to a shop.. They can't help your knee tho.. :D

FWIW, shutting the ignition off also cuts fuel even though the accessories stay on until the vehicle comes to a stop.
Bob

My Rushmore Limited does the same thing. It's not exclusive to M8.

I expected it to be common to all bikes that have a BCM which HD started about the same time they went CAN..

My shop will claim they can fix your knee. For a price of course. I even have friends that can fix others knees for you. For a price of course. snicker

That was priceless!