Jerky steering in 99 GMC burban

[Jessica Howells]

My truck has had some serious steering issues for well over a year now. Going around turns at about 2 o'clock or 10 o'clock my steering wheel jerks pretty hard in the direction I am steering. I have done some research and think it may be the EVO sensor? I live in a very rural area with windy roads, mountains, and lots of trees and a lake. I don't want my steering wheel to jerk and I drive into either of those! I have been able to pretty much predict when this will happen so I can keep 2 hands on the wheel. I try to pull over and turn the truck off, in some cases this fixes the issue for the remainder of the drive. This only happens sporadically. Some days the steering is fine, other days I can't get it to stop jerking no matter what I do. I want the problem fixed. Any help for me on this? Thanks!

[2018GMC]

This is a very common problem with GM's VES (variable effort steering system). The idea of the system is to have it automatically adjust valves In The power steering pump by using the vechiles sensors so you have highly boosted power steering at slow speeds (parking lots, etc) then the system adjusts to minimal boost at higher speeds (highway, etc). This sounds all well and good but the system has many problems especially when taking long "sweeping" turns between 30 - 45 mph. A sensor malfunctions and you get a sudden switch from Minamal to over boost. This is why you feel the jerk sensation.

 

You can replace parts like the EVO sensor but people have reported the problem eventually returns. Some people have just disconnected the electrical plug coming from the powers steering pump so the system stays in the same mode all the time.

 

Here is some more info.

http://my.cardone.com/techdocs/PT%2020-0031.pdf

 

BTW - Thanks for the recall on this GM. LOL

[1997SierraSLT]

Unfortunately, GM will only be proactive and issue a recall once the fatalities start coming in from faulty power steering systems and lawsuits start piling up.

 

In 1997, GM came out with the new VSS (variable speed steering) system which allowed for effortless steering at low speeds and the steering became more firm as speeds increased. It's a horrendous design that consisted of a potentiometer mounted on the steering column to sense steering wheel angle and a power steering pump mounted solenoid valve to increase/decrease line pressure to the steering box based on vehicle speed and steering wheel angle all controlled by the ECM. I've replaced this potentiometer about 5 times over the years as the steering wheel jerks violently out of your hands when cruising down the road at about 40 mpg on a nice sweeping turn. Back in 1999, I filed a complaint with the NHTSA and mine was just one of thousands regarding this issue. I was appalled at GM and NHTSA. Not once did GM issue a TSB or a recall to fix this safety issue. I wonder how many innocent folks have died because of this design flaw?

 

I'm assuming GM paid off NHTSA handsomely to keep their mouths shut and bury the complaints as this design flaw affected over a million 1997 to 1999 GM vehicles including full size trucks, SUV's, and vans. But like any corporation, the bean counters determine how much out of pocket expense there would be as a result of lawsuits vs. the expense of recalling a million plus vehicles. Guess we know which was more economical now.....don't we?