[rpeebles]

Variable Effort Steering - VES

My VES seems to be working erratically. When the road crown changes suddenly, the full assist comes on for a fraction of a second, very annoying. Any ideas about what might be happening, or the most likely what might be happening. Thanks, Roger

95 RM Wagon

 

[Rustbucket Ranger]

My 94 RMW does the same thing. I **believe** the problem is that the steering wheel position sensor gets dirty and stops sending info to the computer system at certain wheel positions.
This problem has been discussed here over the years, under varying names. The simplest solution is to unplug the wheel position sensor (it is at the bottom of the steering column, under the hood). Then it will have one level of steering effort all the time.
It may be possible to use electronic switch cleaner on this unit (for example, from Radio Shack). Comes in a spray can. Might be necessary to remove the sensor from the column temporarily to do this. I plan to do this "one of these years."
The sensor is NLA from Buick or Cadillac (Fleetwood used same unit). There was a similar sensor used on other GM vehicles, that is still available, but would evidently require some adaptation. It is cheap enough that it might be worth buying one and experimenting.

 

[sherlock9c1]

I disassembled and cleaned the sensor. After 145k and 17 years it had some dust and some random bits of goo in it (probably sealing compound from the O-rings, judging by the looks of it).

It is sealed with three o-rings so just spraying the sensor housing won't do anything to clean it. It's also not designed to come apart so you will have to be careful. You can separate the halves using a buck knife or pocket knife. Stick the blade in only deep enough to disengage the lip around the edge, then separate the halves. You will end up with two halves, three o-rings, two telfon washers, and the center disc. I cleaned it with isopropyl alcohol, Q-tips and a clean cotton rag for the final wipe-down.

If you are not good with your hands, do not attempt to open this unit up as you may very likely destroy it in the process. You have been warned.

 

[sherlock9c1]

Just wanted to update 6 months after the fact that this repair is still going just fine. The erratic boost, particularly during highway offramp turns, is gone.

EDIT - FYI, if you'd rather not open this sensor up (or you destroy it in the process of disassembling it) just stick two 5K resistors in the plug and seal the plug up with hot glue or something similar. One should go between the black and green wires, and one should go between the green and red wires. This will tell the computer that the circuit is complete but there is no steering input and thus you will get minimum boost, with minimal pump pressure and thus reduced heat in the power steering system as a side benefit.

 

[96 Black]

Thanks for the two fixes Joel, -- and for making this a stickie.

 

[RollinSlow84]

Just wanted to update 6 months after the fact that this repair is still going just fine. The erratic boost, particularly during highway offramp turns, is gone.

FYI, if you'd rather not open this sensor up (or you destroy it in the process of disassembling it) just stick two 10K resistors in the plug and seal the plug up with hot glue or something similar. This will tell the computer that the circuit is complete but there is no steering input and thus you will get minimum boost, with minimal pump pressure and thus reduced heat in the power steering system as a side benefit.

Could you post a picture or rough sketch? Are the resistors in line (i assume) on one lead? Or literately just stick in the plug?

 

[sherlock9c1]

I'd have to go back and check the Factory Service Manual (FSM) and see.

 

[sherlock9c1]

Update - I just went through the circuit and the error checks in the '94 Factory Service Manual, page 3B5-2. You will need two 5k resistors in series, and physically they'll be wired in the shape of a "3". Put one between the black wire and green wire, and one between the green wire and the red wire. This will give both proper continuity between the supply and ground wires and a stable reference voltage to the sensor input wire. In case you are wondering, the red wire is the 5V supply, the black is the low voltage reference, and the green is the signal output to the module.

In this condition, the variable effort control module will think you are not turning the steering wheel and therefore will provide minimum boost at all times.

 

[Jim Spahr]

On what cars did the VES come as an option?

 

[Goldmaster]

On what cars did the VES come as an option?

I think it was just a Roadmaster/Fleetwood thing. I have never seen the option from the factory on a Caprice/Impala. Maybe I just never ran across one yet though... I'm sure someone will chime in if so.

 

[schofell84]

my 9c1 caprice PS pump seems to give up randomly at idle/low speeds while turning. any ideas?

 

[RYS]

Check for fluid on the belt or a bad belt tensioner. Low speed turning and steering, especially parking, puts a lot of stress on the pump. If you have any fluid on the belt or your tensioner is worn the belt will slip. A bad tensioner will 'jump' while the motor is running.

 

[BandGbodies]

Check for fluid on the belt or a bad belt tensioner. Low speed turning and steering, especially parking, puts a lot of stress on the pump. If you have any fluid on the belt or your tensioner is worn the belt will slip. A bad tensioner will 'jump' while the motor is running.

Especially coolant from the input shaft seal on the water pump. May indicate that your water pump is starting to fail.

 

[Eracer]

You will need two 5k resistors in series, and physically they'll be wired in the shape of a "3". Put one between the black wire and green wire, and one between the green wire and the red wire. This will give both proper continuity between the supply and ground wires and a stable reference voltage to the sensor input wire. In case you are wondering, the red wire is the 5V supply, the black is the low voltage reference, and the green is the signal output to the module.

In this condition, the variable effort control module will think you are not turning the steering wheel and therefore will provide minimum boost at all times.

^^Thanks for that ^^ Mine seems to get choosy in the summer. I thought it was p/s fluid and artificially inseminated it with the turkey baster. Seemed to help.

 

[sherlock9c1]

Update - as of 7/1/2013 - this repair has continued to work great. The car has no erratic boost and drives very nice. All components have 154k on them at this point.

 

[96 Black]

You Dam Right It's Worth TTT

My new FWB has ~53,XXX, but if ghost grab/cloverleaf jerkover raises its head I'll just do Sherlock's resistor bypass. Unplugging the potentiometer is a fast close second choice for fix. I never could tell ANY difference between normal and full boost, and VES seems pretty senseless overall.

 

[Muddobber]

I have read over 3/4 of all the post on this topic and what I have read is y’all cars are doing it changing lanes at interstate speeds
Mine doing this from 25 to what ever
I have a 94 SS and you can be going down a smooth straight road and the all of a sudden it will dart to the right or to the left no rhyme or reason for it
I didn’t notice it till I bought the car
After I got it home and drove it more man it was really noticeable
I replaced all the steering components like the tie rods idlers pitman
Checked all fluids and they looked good
On another forum someone mentioned that the rearend suspension might cause something like that
And got it aligned up
Still doing it
My wife drove it and she won’t drive it again till I fix it
Thanks


Sent from my iPhone using Tapatalk

 

[Fred Kiehl]

There is not really any adjustments that can be used for alignment in the rear suspension. You should check/replace the bushings on the suspension arms and differential, and make sure that there are no broken parts, or detached anchor points. I would also check for a cracked frame rail(s).

You should check the bushings in the front arms, and the alignment shim stacks. If the bushings are failing the car can make sudden changes in alignment, and if the shims have fallen out, it will do some strange tricks. Jack by the front arms, and check for ball joint play as well.

You did not have to replace the Pittman arm, because it is not a wear item, and unless it is bent, it is OK.

 

[96 Black]

Some added info, some you may have already figured:

Impalas do not have VES, so nothing applicable to your case in this thread,
A problem in either the front or the back could appear to be causing an issue in the other end,
As Fred says, missing align shims seems the biggest possibility based on your symptoms as far as the front,
Check close the REAR upper control arm frame mount wear pattern against the frame for possible ovaled frame holes - though that problem usually manifests itself more during accel/braking.
You didn't mention centerlink and it's a maint. item as well
I've seen a really really blown shock get the tire bouncing enough it loses all traction and causes wandering.
If you have not had it up in the air on stands then you need to. It's the only way to inspect close. Get a friend to eyeball everything too for stuff you might not notice.
Worst case you could have a bad balljoint or wallered out spindle hole.

GL Your wife should love that car, not fear it.

 

[fuzzcar]

So just to get this straight. The VES system consists of a pump, steering shaft sensor and damper? Eliminating it requires a new pump only?