Hicas Problem

[gucio]

Hi all

I have a problem with my Hicas on my R32 GTR, now when i drive the car under 80km/h the steering is fine including the direction of the steering wheel. But when i go over 80km/h then i have to turn the steering wheel to the right about 90 degrees for the car to drive straight! and then after a while of this the Hicas light turns on and the you can feel the wheels turn back to the orignal position, the worst thing is that this doesnt happen all the time and so its hard to show the professionals so that they can fix it!

Is the steering sensor stuffed?

any help is appreciated!!!

[gucio]

no one!! , man my hicas must be really stuffed!!

[ebola]

But when i go over 80km/h then i have to turn the steering wheel to the right about 90 degrees for the car to drive straight!

Step 1: DON"T DRIVE THE CAR.

Step 2: Trailer it to a mechanic, and tell him the issue.

Hicas provides about 2 degrees MAX. Think how far the front wheels are turning - do you really think you could even DRIVE a car is the rear wheels where turned on that angle.

also, if the rear wheels were turned as well, you would be 'crab walking' down the road - it'd look like drift.

the reason the hicas light goes on is because you have driven so far without turning the wheel back to straight. unless you are going around a roundabout about 100 times, not likley. This issue causes to to drive with the wheels 'turned'

Seriously, it sounds like your steering rack is stuffed. I'm not kidding about the don't drive it bit. it it happens at 80k, what happens when whatever is wrong FINISHES breaking... hello wall, hello oncoming traffic, hello hospital, and pray you havn't killed someone.

How much is your life wort? or someone elses?

Heck, even the cost of fixing it is cheper than when you crash the car.

reply with what the problem was when you get it fixted.

[gucio]

i dont see how the steering rack is stuffed, cause how would going over a certain speed cause the steering angle to change, the only reason i can see the angle changing is via the hicas cause it switch on over a cartain speed, also the problem comes and goes so my guess is a sensor is stuffed, cause if it was mechanincal then it would occur all the time and the same speed.

[MerlinTheHapyPig]

firstly, i'd suggest installing a lock bar and get rid of hicas all together.

I'd also be checking the tie rod ends for wear / play, and your bushes on the rear, and check the toe. I know you mentioned it probably isn't mechanical, but you should check these things regularly anyway.

Have a look in the Tech /tutorials section on how to get the hicas into diagnostic mode.

If you still can't find the problem, just f**k off the hicas!

[Beer Baron]

it's not HICAS. it's steering rack bushes. they are toast so your rack is sliding around. try this. shake the wheel lef/right quickly and then back to centre. i bet the car drive straight untill you need to turn some corners (then it's out of whack again). that's my guess.

edit: having read the post it may not be, but that's my bet. driving along with the steering wheel off centre for a long time is what's causing the hicas light to come on (steering angle sensor is showing too much steering angle)

[gucio]

thanks guys

yeah iam going to get rid of the hicas, but i was just wondering if it was something else!!

I do have a set of steering rack bushings waiting to go in!

the weird thing is that when i move the steering wheel the steering is exact so what i mean is that when i turn the steering wheel the car turns instantly! no delay and not sliding (on the rack)

[MerlinTheHapyPig]

here is how to get hicas into diagnostic mode

http://www.overflow.250x.com/diagnostics.htm

if you can't get it into diagnostic mode, then i'm 99% sure it will be the steering angle sensor (or perhaps a fault with the computer itself)

[ceedub]

I had the exact same problem on my GTR. I never really understood what the problem was but believe it had to do something with the rear wheels being stuck at the 2 degree angle (whaterver the HICAS does in the back) to compensate the car naturally turns the front wheel as well to go straight, here is a crappy illustration:

/ / front wheels

/ / back wheels

So in theory the car should be going straight down the hwy at an angle - I could never prove it, seems stupid actually.

Anyway things I tried to do to fix it:

wheel alignment, HICAS reset procedure, new tyres, all which worked to some effect but the problem always came back.

don't replace the steering angle sensor, this does not fix the problem.

I later replaced the rear and front bushes (whiteline) and never saw the problem again. The comment about the rear rack in my opinion is correct.

[gucio]

thanks again

and yeah ceedub thats what i though too, it feels like the car is crab walking done the road (well so to speak) but it all happens at speeds above 80 and only sometimes.

Now i have done the wheel aligment and new tires, now all thats left is the rest and bushes. but i will still lock the hicas!!

What bushes did you replace exactly, cause i have had the front castor bushings replaced!

[ceedub]

The "phenomenon" only occurs above 80km/h as the Hicas kicks in above that speed only

The rear bushes are the culprit for sure. I can't remember what they were called (rear castor bushes???) , I'd have to look through my records and I won't be able to do that until I get back from overseas end Aug.

I remember though it was part of the Whiteline stage 1 upgrade or something like that.

Good luck, let us know how you get on.

[gucio]

do you remeber what was included in this whiteline satge 1 upgrade?

will have to replace the rear castors then!