Limp Mode During Sweepers?

[Yazz]

Hi Y'all, a while ago was having some fun on a road full of sweepers. Was in the middle of a long one when Whamoo! VSS, DPS, LIMP. Didn't lift a wheel or anything. Took the key out, said some words, put the key back in and off we went, a bit more carefully.

Took Spydee to the dealer, they checked the BUDS and no codes came up. They said something about sweeping curves...

If this is right, would like to understand the dynamics of what's going on with Nanny in the above situation.

 

[thehawk]

Off-camber sweepers have done this to me more than once.

BTW, I have a technique to cure limp mode that I'm going to propose ... and then stand back for the barrage:

When limp mode or throttle body stuff happens in the middle of a ryde, I just reach down and turn the key off for a count of 1 or 2. When I turn it back on, the 'latched' fault doesn't clear but the immediate action (big orange screen) does.

Just my .02 ... you do this at your own risk. I'm just saying it works for me. Wouldn't want to do it for an engine oil light, of course ... but it works for some of the weird, non-recurring stuff.

Anybody else want to weigh in??

thehawk

 

[NancysToy]

I have seen this happen. My best guess is that it is a mismatch between the steering angle sensor and steering torque sensor...with maybe a little help from the yaw sensor reading. It also seems to have a timeing factor...happens in very long sweepers. In a sweeper with a lot of banking, there is less steering torque than normal. I think that enters into it, and the computer can't understand the mismatched sensor readings, so it defaults to limp mode since it could make a mistake otherwise. JMHO

In my case, the SAS was a little out of calibration. Did they check the steering sensor zero readings when they hooked up to BUDS?

 

[Yazz]

Off-camber sweepers have done this to me more than once.

BTW, I have a technique to cure limp mode that I'm going to propose ... and then stand back for the barrage:

When limp mode or throttle body stuff happens in the middle of a ryde, I just reach down and turn the key off for a count of 1 or 2. When I turn it back on, the 'latched' fault doesn't clear but the immediate action (big orange screen) does.

Just my .02 ... you do this at your own risk. I'm just saying it works for me. Wouldn't want to do it for an engine oil light, of course ... but it works for some of the weird, non-recurring stuff.

Anybody else want to weigh in??

thehawk

Yup, it was a left hand sweeper on a hipped road. Glad I'm not the only one this has happened to!

As for your technique... Mine happened on a four lane road with wide shoulders and a car every two miles or so. It was a safe place to pull over and mutter for a few minutes.

But, if limp mode hits on something like a busy sweeping overpass, I'll try your technique. IMHO it's safer than pulling over to the shoulder and trusting nobody will hit you.

 

[Yazz]

I have seen this happen. My best guess is that it is a mismatch between the steering angle sensor and steering torque sensor...with maybe a little help from the yaw sensor reading. It also seems to have a timeing factor...happens in very long sweepers. In a sweeper with a lot of banking, there is less steering torque than normal. I think that enters into it, and the computer can't understand the mismatched sensor readings, so it defaults to limp mode since it could make a mistake otherwise. JMHO

In my case, the SAS was a little out of calibration. Did they check the steering sensor zero readings when they hooked up to BUDS?

It was a long left hand sweeper on a hipped road. Didn't even make it all the way through the curve. Was hanging like a monkey to keep the inside wheel down, so yeah, can now understand why Nanny got confused with conflicting input. Better safe than sorry...

Not sure if they checked the steering zero readings. Think they were looking for codes.

Have gone into limp mode twice now. First one was a loose fuse, and this is the second time. Have ridden her alot harder through twisties with no issues. Thats why the sweeper limp mode was such a quandary.

Scotty, thanks for explaining the ins and outs of a sweeper limp!

 

[Bob Denman]

:shocked: Another fellow was talking about it happening to him on the banks at Talladega... I was guessing that the yaw and steering angle sonsors were having a tug of war for THAT one!

 

[mastertek2000]

they really need to raise the limit on this

 

[flamingobabe]

Bet that was kinda scary...I went into Limp Mode (due to something, a screw, bending 6 sprockets on the ABS wheel) doing maybe 20mph in a left-hand turn...see y'all in ABQ/Durango

 

[Yazz]

:shocked: Another fellow was talking about it happening to him on the banks at Talladega... I was guessing that the yaw and steering angle sonsors were having a tug of war for THAT one!

Would love to get out on a race track on of these years!
From now on, if doing a sweeper and Nanny kicks in, instead of going :gaah:, I'll go :yes:

they really need to raise the limit on this

Don't want to find out how hard I can power a curve before Spydee flips. nojoke

Bet that was kinda scary...I went into Limp Mode (due to something, a screw, bending 6 sprockets on the ABS wheel) doing maybe 20mph in a left-hand turn...see y'all in ABQ/Durango

The scary part was restarting the engine. Didn't know what was going to happen.
Hope you weren't too far from home when your ABS got chewed up!

Looking forward to seeing Y'all in ABQ and Durango! :thumbup:

 

[Bob Denman]

We know for a fact that they have track days at Daytona, Talledega and Pocono...
Maybe Texas... :dontknow: You might want to do a little digging and see if they've got one too... :thumbup:
We were told that renting Talledega woud cost $10,000 for a day; Less than $1.25/Spyderlover... :shocked: :2thumbs:

 

[daveinva]

Resurrecting an old thread just to share that **I** got my first limp mode this weekend! VSS fault while mowing through the twisties in West Virginia. Not sure if it was a long sweeper-- happened Friday, don't recall where precisely it occurred but I was heading up a mountain at the time. That limp mode, it's QUITE the surprise when it hits, ain't it? :yikes:.

Pulled off to the side, shut the bike off, took the key out and walked away for a minute. Started right back up, no limp mode, no problems the rest of the weekend even with spirited riding (thank goodness-- I was 200+ miles from home!).

Anyway, I'm guessing this was the problem, and I'll be sure to ask my tech to check the steering sensor calibration when I get it serviced next.

 

[NancysToy]

The problem can be enhanced by minor steering sensor miscalibration, but it can happen in a long turn or a prolonged side wind with everthing precisely calibrated. What happens, the way it was explained to me, is that the steering angle sensor and the steering torque sensor fail to match, due to the other forces acting on the Spyder. This isn't unusual during turns, and in most cases the mismatch would triggers the VSS (aka "Nanny") but for minor mismatches that are normally ignored, the computer reads the extended duration of the mismatch, times out, and figures that a sensor is out of calibration, triggering limp mode and disabling the DPS assist. It seldom happens and is easy to reset, as you found. Just a little quirk.

PS, I understand that a prolongued turn in one direction can trick the computer into thinking the yaw sensor is whacko, too, so that can be a possibility sometimes.

 

[daveinva]

The problem can be enhanced by minor steering sensor miscalibration, but it can happen in a long turn or a prolonged side wind with everthing precisely calibrated. What happens, the way it was explained to me, is that the steering angle sensor and the steering torque sensor fail to match, due to the other forces acting on the Spyder. This isn't unusual during turns, and in most cases the mismatch would triggers the VSS (aka "Nanny") but for minor mismatches that are normally ignored, the computer reads the extended duration of the mismatch, times out, and figures that a sensor is out of calibration, triggering limp mode and disabling the DPS assist. It seldom happens and is easy to reset, as you found. Just a little quirk.

Yeah, I was fearful it would happen again but it never did, even under similar conditions, so I'm not worried. I'm about 1500 miles out from my next service appointment, I'll have them run a check then just to be on the safe side.