VSS Faults, what do you think is causing this.

[Jcummins]

VSS Faults what do you think the cause is?

The first VSS fault that I had I was beside the road with the spider idling foot on the brake looking at a map and suddenly the VSS fault occurred. That same day I had a similar occurrence and I related it to sitting, idling and having my foot on the brake. Fast forward to today and since then the VSS fault has been occurring more regularly when I first start the spider after it sit for a while. It seems like once I get out and continue with the ride it doesn't really occur. And here again typically I have my foot on the brake. So what I did, I put the bike in park put it in a neutral and the next time I started it I made a point of not touching the brake. I simply hit the mode button, start and the spider started with no fault. As soon as I put my foot on the brake so I could shift into gear....VSS fault.

This afternoon I check the level of the brake fluid and it is exactly on the max fill line. I've got the three thousand mile oil change coming up and I'll have the dealer check all of this out but until then does anyone have an idea of what the issue is here. It obviously has something to do with a brake pedal .

 

[Bfromla]

Odd indeed. Thought had to be moving for VSS Faults:dontknow::dontknow: tried see if there any codes? & just about by default: battery clean & tight?

 

[Jcummins]

Odd indeed. Thought had to be moving for VSS Faults:dontknow::dontknow: tried see if there any codes? & just about by default: battery clean & tight?

Need to check battery, got battery tender pigtails on it.. Think it will be fine, but I meant to check that when I checked the fluid.

This is on a 2020 RTL.

 

[Snowbelt Spyder]

Hey J. So, you are on the right track about the brake pedal being related. Today, as well as from the beginning, when the brake pedal is depressed far enough to activate the brake light switch, the VSS system then checks to see if there is a rise in brake fluid pressure. (This is not the same as the Low Pressure Switch pressure check) It's a very small number. On mine, it's 10#. If it is not above the specified value, it triggers a fault, and in the past it triggered a Limp Home Mode. We always called this the "riding the brake" Limp Home Mode. This is alluded to in your manual on the page about the brake pedal. Now, maybe they changed the software for 2020, or maybe you didn't get a Limp Home Mode because you weren't moving at the time, I don't know. But, based on your observations, your issue doesn't occur when you are out riding, using the brakes normally, stopped at stop lights, etc, but only when already stopped. It just might be that you are applying a very light pressure on the pedal in your driveway, looking at maps, etc. Light enough to trigger the fault.

You can experiment with this by doing what you normally do that brings on this fault, except pressing the pedal a lot harder. If the fault does not occur, then this is the issue. It still may not be right. You are under warranty. There may be a rogue air bubble in your system and a system bleeding is in order. Or the dealer may have to do a brake pressure adaptation or similar with BUDS. If you can cause this to be repeatable, than by all means demonstrate it to your dealer at your next service and have it taken care of.

 

[Jcummins]

Hey J. So, you are on the right track about the brake pedal being related. Today, as well as from the beginning, when the brake pedal is depressed far enough to activate the brake light switch, the VSS system then checks to see if there is a rise in brake fluid pressure. (This is not the same as the Low Pressure Switch pressure check) It's a very small number. On mine, it's 10#. If it is not above the specified value, it triggers a fault, and in the past it triggered a Limp Home Mode. We always called this the "riding the brake" Limp Home Mode. This is alluded to in your manual on the page about the brake pedal. Now, maybe they changed the software for 2020, or maybe you didn't get a Limp Home Mode because you weren't moving at the time, I don't know. But, based on your observations, your issue doesn't occur when you are out riding, using the brakes normally, stopped at stop lights, etc, but only when already stopped. It just might be that you are applying a very light pressure on the pedal in your driveway, looking at maps, etc. Light enough to trigger the fault.

You can experiment with this by doing what you normally do that brings on this fault, except pressing the pedal a lot harder. If the fault does not occur, then this is the issue. It still may not be right. You are under warranty. There may be a rogue air bubble in your system and a system bleeding is in order. Or the dealer may have to do a brake pressure adaptation or similar with BUDS. If you can cause this to be repeatable, than by all means demonstrate it to your dealer at your next service and have it taken care of.

Interesting. I do not brake hard. Just my style. I'll experiment with your ideas. Thanks.

 

[Jcummins]

For anyone interested I think I might have found the problem. I checked the battery connections and although they were fairly tight they weren't real real snug. I tightened them as much as I dared started the spider and no fault so we'll see.

 

[Bfromla]

As Blue knight would say “Add some star washers to battery connections”:thumbup: