Lean angle sensor

I have been chasing an intermittent problem for a couple of weeks when the bike was fully warm and finally the bike died. My first symptom was a persistent miss at about 1/3 throttle when fully warmed. Below that opening it ran fine as well as at WOT. I checked the self diagnostic codes and the throttle position sensor, lean angle sensor, intake pressure sensor, speed sensor and coolant temp sensors were listed. Checked all of those items using the self diagnostic system and they all were with in the parameters. Odd hat they all would fail at the same time. Next symptom was the speedo readout started showing random numbers, first at the same throttle opening as the miss. I could repeat the symptom at an indicated 35-36 mph. Again I checked the codes same as before. Then the eradict speedo reading moved up to 45 mph. Checked the codes same as before but the EXUP servo motor was included. So I checked things again. The bike finally died and would not restart, checked the fuses all OK so I called my wife and retrieved the bike with a trailer. Now the lean angle sensor did not check out. I opened up the sensor and locked the weight in place with silicone,let it sit over night and put over 130 miles on it this afternoon with no problems. The common thread between all the sensors that showed up on the self diagnostics is the black with blue wire that connects to the crank position sensor and to the ECU. I think the weight in the lean angle sensor became misaligned or lose and at certain vibration frequencies was affecting the signal to the ECU.

taking the lean angle sensor apart was easy and allowed reassembly. After disconnecting it and removing it from the bike remove the whitish connector ring from the black housing by carefully prying the black housing at the four points were the ring locks in. Remove the rubbery gasket and carefully pull the end cap and enclosed circuit board from the housing by grabbing one of the metal terminals with a needle nose pliers. The weight pivots from a hole in the circuit board and a notch in an extension molded with the end cap. Use a small dab of RTV between the weight and the circuit board. The weight should be oriented so that it hangs down or opposite the up side of the housing. reassemble before the sealant sets up so the weight will be in the proper alignment on the horizontal axis. Let sit in the as installed position over night.

Sorry no pictures, I was too engrossed in solving the problem.

Wow,you know I was kinda thrilled to have FI after years of carbs.But now I don't know.
Lean Angle sensor? what kinda BS is that on a dual-sport? Then I hear that my 2008 with VIN of 700,fuel pump is probably gonna fail.Great!
Anyhow,curious to find out what your fix is.Good Luck.

inroads wrote:

Wow,you know I was kinda thrilled to have FI after years of carbs.But now I don't know.
Lean Angle sensor? what kinda BS is that on a dual-sport? Then I hear that my 2008 with VIN of 700,fuel pump is probably gonna fail.Great!
Anyhow,curious to find out what your fix is.Good Luck.

the lean angle sensor actually makes a lot of sense, especially on a dual sport. it's meant to cut power in case of a crash. prevent things like fires if some gasoline spilled, or from stopping the chain chewing through your leg as you are passed out next to the bike, with it still in gear (horror story I'm sure many here have heard before).

as far as the lean sensor goes, I haven't heard many cases of it failing (this being the first one), but everything has a certain failure probability, so even our lean sensor (or side stand switch sensor, clutch position sensor) probably have a failure rate of a few percent.

to each his own about FI and carbs. I much prefer FI, just yesterday after 10 hours of rain, I went to the bike parking lot and mine started up no problem as usual. the folks on the older bikes with carbs were messing with their choke, trying to get the bike to idle correctly bla bla. eventually they made it underway, but some would still stall at the lights for at least another 10 minutes.

inroads wrote:

Wow,you know I was kinda thrilled to have FI after years of carbs.But now I don't know.
Lean Angle sensor? what kinda BS is that on a dual-sport? Then I hear that my 2008 with VIN of 700,fuel pump is probably gonna fail.Great!
Anyhow,curious to find out what your fix is.Good Luck.

Easy there dude....I've got a 2008 with original fuel pump and just clicked over 11,000 miles.

Lean angle sensor is a smart thing to have - but as you've read, it can be disabled if it's an issue.

Dump your bike in a deep puddle, have your bike fall onto your leg, or any fall at all really and you'll be glad there's a mechanism that'll shut off the bike.

Might be a good idea on paper but I think it is just something else to go wrong.Gotta keep it simple.
I guess this is something that came along with FI.Maybe prevents the fuel pump from running dry in the event of a spill.
in these days of ethanol FI is looking better but it still isn't fixable in the field like carbs.pro's and cons for both.

It's far more than a "good idea on paper".


It's a good idea in reality.


But you're always free to disable it.

When it's working!

Shitloads of us have them and they all work fine.

I've only heard of them not working when people start messing with them.

side stand sensor-gone
clutch position sensor-gone
AIS-gone
exup-gone
lean angle sensor-gone
Get the picture? In my world its about removing systems that aren't necessary because it narrows down the field when problems arise.
I'm more comfortable eliminating something that can shut off the the fuel flow prematurely when I want it to flow.
That faint remote scenario of needed that thing adds complexity.
You keep it,you need that security,I don't.In my world it's a liability that can fail out in the boonies.
Lot's of bikes and lots of miles without it before.
But hey,that's just me.
keeping it simple means your not snowballed with systems when your trying to troubleshoot in the field.
just my 2 cents.

I have my sensor all apart and am not sure where I am supposed to put the RTV or what the point of the RTV is?
I see in the weight it appears to have a magnet. Couldn't I just remove the weight and put the sensor back in the bike with no weight in it?
Is the point of the RTV to make the weight not move anymore? It appears you'd need a lot as there is a decent gap between the weight and the circuit board.
Please help as I'm trying to figure this out and just not sure how to proceed.

PrettyRicky218 wrote:

I have my sensor all apart and am not sure where I am supposed to put the RTV or what the point of the RTV is?  
I see in the weight it appears to have a magnet.  Couldn't I just remove the weight and put the sensor back in the bike with no weight in it?
Is the point of the RTV to make the weight not move anymore?  It appears you'd need a lot as there is a decent gap between the weight and the circuit board.
Please help as I'm trying to figure this out and just not sure how to proceed.

I know this is late, but I think the RTV would be applied to where the prongs that the magnet pivot on to secure it from pivoting.  Google images "Yamaha Lean Sensor Eliminate" for some pictures.