Speed sensivtive steering

nhproxr · July 7, 2004

I have speed sensitive steering on my '98 Yukon and was just wondering what it is all about. My truck is starting to drift a little in my lane at highway speeds. I know I need new shocks wondering if this speed sensitive steering is also a factor, or maybe should be doing the obvious and checking all rod ends and ball joints.

GMCTech · July 7, 2004

Speed sensitive steering or VSES (Variable Speed Effort Steering) is designed to make steering in parking lots, etc. easier, and to not be so sensitive at highway speeds.

The power assist is controlled by a small valve on the back of your power steering pump. It receives input from a VSES module. THe module factors the vehicle speed, and compares it to steering wheel speed. There really are only a couple parts - the vehicle speed sensor, the handwheel position/speed sensor, the variable speed steering valve, and the module to control it.

90% of the time the problem is in the handwheel speed sensor, and there is a code that can be read to indicate a fault in that sensor.

Hope this helps.

nhproxr · July 8, 2004

So could this cause my drifting at highway speeds??? Also I have one of those $150 scanners you get at Auto Zone, don't imagine this tool would pick up the code if this thing was a problem?

GMCTech · July 8, 2004

More likely it would cause a condition that would make your steering wheel very touchy. Just barely turning to the right or left would feel like you are oversteering.

More likely you have a tire or alignment problem.

Always check your tire pressures first, set to pressures listed on driver's door. Then drive again. While rechecking your pressures, lookat tire condition, maybe it is time to rotate your tires. Check especially for "chopping" on the inside edge of the front tires.

If all is good with pressures and condition, have the front end inspected thoroughly. And make sure it is well greased.

If still everything looks good, it may be time for alignment. Let the alignment shop know what it is doing so they can address that concern.

Hope this helps.

nhproxr · July 8, 2004

Tires are good, wearing nice and flat, I rotate them every 8000 miles or so. Front end is tight and was greased a couple thousand miles ago. Might need an alignment but at slow speeds truck does not pull and like I said tires are wearing as flat as can be.

I did notice last night though that it does act like I am always over correcting myself at highway speeds. Truck also does have some bounce over uneven spots that seems to unsettle the truck, needs shocks bad.

GMCTech · July 9, 2004

Does your truck have a steering stabilizer?

If so, you may need to replace that as well when you have your shocks done.

Hope this helps.

GOT_NITRO? · July 9, 2004

I have a similar situation on the highway. When crusing at 60 - 70 mph through a long sweeping turn the steering wheel will all of a sudden turn much farther than the amount I was holding it at. It's like it shifts from firm to soft very quickly. The same as if someone would jerk the wheel while you are driving. I almost lost i a couple of times.....added a steering stabilizer....helped a little.....used lucas power steering additive.......better but still not firm enough. Is this a malfunctioning speed sensitive steering unit. Can it be removed?????

ZR Rider · July 12, 2004

Same problem on my 97 Seirra!!

When I turn the wheel in a corner... it just seem to let go and turn more! Not a big deal to me as I am use to it... just worry about it if my wife drives it or on wet roads!!

Where is the control mounted?? Any chance of a digital pic??

ZR Rider · July 12, 2004

Here's another thing I have noticed recently. When turnning and very low speeds forwards or backwards I get a growling noise from the steering box area. Ant thoughts on this one??