Having a problem with my Electronic Power Steering (EPS).
Intermittently the EPS appears to be jerking the handlebars moderately from side to side while travelling down the trail at slow to moderate speeds. If I steer side to side on a 6' wide trail or speed up it does not happen. Appears to be more prevelent for a while after going thru water, thus thinking about applying di-electric to connectors. But "which connector" in particular (obviously the EPS motor)?
- tire pressure is correct
- alignment appears ok (slight toe-in)
- don't think the front bearings are worn too bad at 5000km (will check)
- rims clear of mud causing out of balance issue
Any other ideas?

It must be something electrical if it happens after dunking in water. Found a viewable/printable online manual for 07-08 Grizzly 700. Check into the steering diagnostics and checks. Maybe the torque sensor is getting false readings . The service manual is a start.
07-08 Grizzly 700

I just have had the same problem a couple of days ago. My steering keeps pulling to the left, so hard I had to use my foot to keep the quad steering in a straight enough line to limp it back to a spot to pick it up with my truck. I couldn't believe the power in the steering. I did nothing to abuse the quad and only have 1200km on it. I did go through a muddy hole but nothing splashed above the foot boards and the EPS motor is dry. I was told by a mechanic to disconnect the power to the control box to see if that help and then to get it checked out. If I have to replace the control box and/or the EPS motor it could run $1000+, so may have a non-EPS quad for a while. If you have any info to pass along it would be appreciated and if I get any I will post it.

If you can manage to get your trail speed up the impact is much reduced.

Apparently my used unit has a Yamaha 3yr extended warranty, so the dealer will be looking at this issue as well as my non-functioning diff-lock.

Mine is definately moisture related.

Toadman wrote:

Having a problem with my Electronic Power Steering (EPS). Intermittently the EPS appears to be jerking the handlebars moderately from side to side while travelling down the trail at slow to moderate speeds. If I steer side to side on a 6' wide trail or speed up it does not happen. Appears to be more prevelent for a while after going thru water, thus thinking about applying di-electric to connectors. But "which connector" in particular (obviously the EPS motor)? - tire pressure is correct - alignment appears ok (slight toe-in) - don't think the front bearings are worn too bad at 5000km (will check) - rims clear of mud causing out of balance issue Any other ideas?

Sounds like maybe a front outer cv problem to me. one may getting water in it and binding. I've had the exact same problem before on a non eps quad.

Check you boots real good for any tiny tears. They could also be getting some water even if the boots arent torn. Would cost you nothin to pull back the boots and check them. A whole lot cheaper than a trip to the stealer

Thanks callen65, that did get me thinkin about a CV or front diff lock problem for a second.
But sometimes when it happens...even when stopped the handlebars are near impossible to turn in either direction. That would not be a CV problem...would it. Who would have thought that motor could produce that much resistance?
Funny thing that I have noticed is that it is more effected by muddy soup than clean water.
Gonna try to clean and apply di-electric grease to the motor connections before this Sunday's club ride. We will see if that helps, as there is always some water hole that you can't go around.

I didnt' get the EPS on my '08 700 Grizz. I didn't think I'd need it but it would be nice when plowing snow. Anyway, when it fails like that, isn't there a fuse you could pull to disable it rather than manually fight it till you get to the truck or get home? Or will that shut down other necessary items for normal operation?

Update: Applied di-electric to the 4-wire control connections to the EPS module, but that did NOT solve the problem. Did not apply to the larger gauge(Red/Black) power supply connections, as it is obviously getting power.
One thing I did notice is that there is a vent tube for the module. Why I am not sure.
Fuses are probably under the front pod/rack area, which is a pain with a front box installed.

I had this problem with my 08 700 efi non EPS found a small cut in the boot after I cleaned it off. Took it the dealer then said it was my left front outer joint was locking up. This problem nearly killed me when it took me off the trail. Luckly im a bigger guy fought the handle bar got it back to my truck.

Toadman
There are two connections on the right side. just follow the wires from the eps motor.

sled05, Yes one is the control circuity wiring and the other is power. Applied dielectric to the control wire connection without success. As long as I stay out of the deep water I do not have issues.

Toadman ... have ya got this issue fixed yet ?? .... I'm thinking of putting PS on my 660, so I'm kinda interested in how this is going for ya

Gunny, nope haven't got out on the quad much lately since been working stupid long hours. Last few times I did get out I tried to stay out of the deep water and the problem was kept at bay as much as possible. Apparently I have until March to get it looked at under extended warranty....at this rate it might take until then to get it into the shop.

I have now heard of a couple of other people that are having the same issue without a solution. Has anybody else had the issue and been able to solve it?

Dang ... well don't wait to long Toadman ... time flies when yer hav'in fun ... I mean ... I thought I had just put the Christmas lights away & look what happened ... time to put'em back up