99 Suburban Power Steering Proble

When driving and turning the steering wheel slightly, the steering wheel grabs for a second or two, then releases. I noticed this less when my front tires were worn down but it returned after I put new tires on. Anyone experience this problem?

I believe that the problem you are experiencing is a failure with the steering wheel position sensor.It's located at the base of the steering column before it passes through the firewall.Replacing this sensor should cure the problem.
chuck's

You also need to make sure it's not something mechanical. Disconnect the electrical plug on the power steering pump at the bottom back side. This removes the signal from the position sensor for the variable ratio system. I did this 2 years ago and been driving it that way ever since. One of these days when I get 'round to it I'll replace the position sensor.

thanks for the info. I'll see if the posiiton sensor is bad.

i'm having the same problems, can u post the results of what happened ?

I had the same prob. Replace the steering sensor. I believe it is called the EVO sensor if memory serves me right. Kind of a pain to replace, One tip - you have to disconnect the battery 1 hour before starting your project so the Air bag will not deploy. BUT you can do it yourself it is not worth paying the Dealership to pay for it. I'm a girl and not a mechanic and I did it.
Learned how to do it from this website and a owners repair manual.

i'm having the same problems, can u post the results of what happened ?

Our steering wheel doesn't grab, but instead seems to slip (i.e. take liberties in turning too much) sometimes. It's not really that bad, but has a way of getting your attention back to the road if you know what I mean. I thought that I had read someplace that some type of grease packing could cause a problem like mine. Any ideas?

Have you had any front end work recently?I'm wondering if there is not enough caster to help the wheels return to straight ahead?
chuck's

i'm having more of the problem your having, meaning the steering wheel will sort of slip.

Ok here is what mine did:
I would be driving and usually while turning, it would sort of jerk and then feel really "loose" I could suddenly turn the steering wheel much further, but the wheels didn't necessarily turn, then it would grab again and the wheels would turn. I would jump and immediatly correct my steering. It wasn't bad at first, but it gradually got worse. I tried driving around in lower gears to keep the RPMs up to see if that fixed the problem. It sort of lessened it, but then when I slowed down to make a turn, it would happen again. I thought it may have something to do with the alignment or front end, so I had the pitman arm replaced and the front end aligned, still had problem. Took it to the dealership for a diagnostic and they said it was the EVO thing. THe mechanic was really nice and told me to take it home and have my husband fix it there. It wasn't wortht the money to pay him to do it. If what I said sounds like the same problem you are having, guess what...... I tried to explain it the best I could, but remember I am female and we are more into showing how things are broken and not so good at explaining how things are broken. Hopefully I made some sense.
Jodi

Our steering wheel doesn't grab, but instead seems to slip (i.e. take liberties in turning too much) sometimes. It's not really that bad, but has a way of getting your attention back to the road if you know what I mean. I thought that I had read someplace that some type of grease packing could cause a problem like mine. Any ideas?

Our steering wheel doesn't grab, but instead seems to slip (i.e. take liberties in turning too much) sometimes. It's not really that bad, but has a way of getting your attention back to the road if you know what I mean. I thought that I had read someplace that some type of grease packing could cause a problem like mine. Any ideas?

Any Idea's???? Check out the 3rd post in this line. It's the easiest way to see if it's electrical or mechanical. Just do it and drive around town. By the way the "EVO" (Electronic Variable Orfice System) is incorporated with the "PassLock" module located under the dash at the radio area. The steering wheel sensor(HWSS) is located in the lower bearing of the steering column. If it's electrical this is likely the source of the problem.

Well, glad you know what it is called. I couldn't remember. I replaced both the steering wheel sensor and the evo sensor. As I said in my first post, I was guessing at the name. The sensor I am talking about is the one located in the steering column itself, on the inside of the car. I am pretty sure it is called an EVO sensor, in any case it is a sensor of some sort. It iwas located just above the lower knuckle of the steering column before the steering column passes through the firewall. I think the thing you are refering to as the PassLock module located on the right side under the "radio" area is called a diode. I replaced that too, but for other problems.
Jodi

Any Idea's???? Check out the 3rd post in this line. It's the easiest way to see if it's electrical or mechanical. Just do it and drive around town. By the way the "EVO" (Electronic Variable Orfice System) is incorporated with the "PassLock" module located under the dash at the radio area. The steering wheel sensor(HWSS) is located in the lower bearing of the steering column. If it's electrical this is likely the source of the problem.

You also need to make sure it's not something mechanical. Disconnect the electrical plug on the power steering pump at the bottom back side. This removes the signal from the position sensor for the variable ratio system. I did this 2 years ago and been driving it that way ever since. One of these days when I get 'round to it I'll replace the position sensor.

Does this affect the power stearing function of the pump ? I am having same problem, and if the fix is as easay as unplugging a basicly non essential item al the better.

Is this on your "new" Sub? Disconnecting the plug at the pump will "definitely" affect the steering as it will make it easier at all speeds. This is something you should only do to see if the problem is mechanical or electrical. If the problem goes away, replace the steering sensor ASAP and reconnect the pump wiring. The steering sensor is a 90% cure for this problem.

Is this on your "new" Sub? Disconnecting the plug at the pump will "definitely" affect the steering as it will make it easier at all speeds. This is something you should only do to see if the problem is mechanical or electrical. If the problem goes away, replace the steering sensor ASAP and reconnect the pump wiring. The steering sensor is a 90% cure for this problem.

Front likes to wander a little, with an occasional jerk to either side when going over a rut or pot hole. Steering wheel will still be straight, but wheels are going a diferent direction.

Is this on your "new" Sub? Disconnecting the plug at the pump will "definitely" affect the steering as it will make it easier at all speeds. This is something you should only do to see if the problem is mechanical or electrical. If the problem goes away, replace the steering sensor ASAP and reconnect the pump wiring. The steering sensor is a 90% cure for this problem.

Same symptoms on my 98 with 122K, Steering Sensor fixed the problem, Thanks