dc893

My power steering has no feedback what so ever. The steering is super easy to turn and very light. When I turn there is zero feedback to the steering wheel. Every time I am driving and the road surfaces are different on the left or right side the car feels unpredictable. The steering wheel jumps all over the place when I hit bumps or on a windy day it makes it scary to drive.

I have not changed any parts yet. I have new sway bar links to install, but that is another issue.

I have also searched, but did not find anything.

Maybe tie rods or the steering rack?

Steering damper?

Anybody know what could cause the steering to feel like that?

1992 LS with about 300,000 miles on it.

Thanks again for any help.

cobalt91

not sure what you mean by feedback. The LS is a luxury barge, so the steering is pretty numb to begin with. Broken sway bar links can contribute to the problem. I'm gonna say check both the tierods and balljoints along with the radius arm bushings.

LScowboyLS

with 300k miles, I would be on my 3rd set of inner and outer tie rod ends, the parts are relatively cheap, the job is easier than most, and it will give you that new car firm steering with no slop - I replace mine every 100k, just for the new car feel!

KYLS400

Owned this 95 Lexus LS 400 with 147K for about 2 yrs.
Already replaced caps in ECU - thanks again to Yamae and LSCowboyLS.

Complained of too much power steering assist at speed. Could hardly keep car in lane of traffic.
Stalked here looking for solution.
Found thread and link - where another had installed a potentiometer (think volume control) on his power steering computer and obtained a better feel.
Decided to see if my PS ECU was working. Found fuse to PS ECU - pulled fuse (careful, it controls your shift-lock, you'll have to work around this) and went for a short drive.
FIXED - I HAD FEEL AT SPEED!

***Don't drive for long - somehow, this fuse also stops your alternator from charging your battery. You will be driving on battery only, until you plug fuse back in.****
Ask me how I know....duh.

Since an OEM was over $300, I ordered one for $36 from a wrecking yard off E-bay.
PN-89650-50090
Finding it was a challenge - had to locate it by feel - laying on my back in driver's floorboard, and feeling above brake pedal.
Old ECU slides on a bracket. I pulled it off, unplugged old one -plugged in new one. FIXED.
Steering feel at speed. I can keep car in lane.

Broke open old one. Found three capacitors very reminiscent of those in the bad MAIN ECU - that Yamae and LSCowboyLS- have helped so many with.
I can post pics if there is any interest.

LScowboyLS

wut? yes!! very much interest! - post to my main capacitor leaking thread as well!

you have made a game-changing breakthough, my friend! - good job!

YoshiMan

Hmmm... I may have to take a look at that as well, my 95 kinda has the same issue at freeway speeds, almost like the variable steering ratio stays the same from a dead stop to 75 MPH.

I always just figured that was the way it was intended to be and haven't ever looked further into it!

LScowboyLS

please also post the writing on all of the original caps and I will post back the current correct replacement caps!

KYLS400 - you might as well get ready to order the caps for the wrecking yard unit, it will deteriorate in the same way your original did!

RA40

iTrader: (6)

KYLS400, yes, let's see pics of that steering ECU.

LScowboyLS

this is huge, first ECU caps, then cluster caps, then TRAC caps, now PS unit caps, what is the next module for failing caps?

dc893

My issue ended up being sway bar links that were bad but this is interesting.

YoshiMan

Maybe the airbag module? Kinda hard to test that one though!

KYLS400

Here's what the PS ECU looks like:


Laying on your back in the drivers side footwell, the PS ECU is located above the Steering wheel Tilt/Telescopic control unit.
You're looking up at it here.



Reach up with your left hand, on top of the Tilt Telescopic control box, you'll find a 2"x2" box that is held on with a slide on bracket. (I just pulled mine off). Replaced mine with junk yard unit. Original is available, but I was not willing to pay over $300.



Plugged wiring into blue connector on junkyard PS ECU





Insides of PS ECU.
With blue connector closest to you, back left brown cap is 10v, 22uf
Back middle brown cap is 50v, 1uf.
Back right brown cap is 50v, 47uf.

LScowboyLS

can you tell us the other markings on each cap (besides the capacitance and voltage) such as other letters, numbers or logos

Yamae

I recognize the one at top right corner. It must be not a Nichicon's but a Nippon Chemicon's. The mark of the safe valve looks "Y". Judging from the color, it must be the type KME which is widely used in different controllers except the main ECU which has Nichicon's PF(M) or PF(R).

The KME is the standard and 105 degrees C series. It does not contain any infamous quaternaty ammonium salt inside and the leg will not be corroded. Usually it lasts longer than those in the main ECU. But remember that electrolytic capacitors evaporate the liquid inside as aged and the capacitance decreases little by little and ends the life someday.

LScowboyLS

I am going to predict that the top left cap in the pic (the 22uF) is a Nippon Chemi-con special BP (bi-polar) type!