Hicas ??????

[ex supra now skyline]

hi all got a problem well 2 problems with my skyline r33 gtst m reg

1/ what is HICAS and what does it mean as mine keeps poppin up on my dash when driving

2/ my oil is going from 4 down to 2ish some times a bit over 2 and some times a bit under 2 . does it mean i need a oil change or is it somthing far worse

[Squeak]

this may be of some help regarding the HICAS: HICAS Diagnostic Mode

[gtrkid]

Originally Posted by ex supra now skyline

hi all got a problem well 2 problems with my skyline r33 gtst m reg

1/ what is HICAS and what does it mean as mine keeps poppin up on my dash when driving

2/ my oil is going from 4 down to 2ish some times a bit over 2 and some times a bit under 2 . does it mean i need a oil change or is it somthing far worse

not sure about the hicas its beond me.is your oil pressure up and down when your driving?stopped?hot or cold?

[ex supra now skyline]

driving

[Jez-R32 GTR]

For the HICAS check your power steering fluid levels. The HICAS warning will come on when the level is low.

I get 4 bar on cold starting and it drops to about 2 bar when warm. The oil pressure will go up and down with engine speed.

[RoboPope]

Hicas is electric on the 33, I would suggest an aftermarket steering wheel with the wrong boss.

change the oil anyway, it wont hurt

Pope

[Anthonyskyline]

do you have many problems with the hicas?

[Squeak]

Some do, some don't. A few people fit HICAS lock out bars to disable the HICAS

[Anthonyskyline]

does the hicas make big different to the handling or is it worth fitting the lock bar

[Rich B]

just had my lock bar fitted and it turns in and holds line MUCH better now

[andybob]

hicas locks rock i got mine when i found i couldnt hold a drift for any lenght of time and got close to having acciedents to me its one of those safety features that should of stayed in the gtr and only the gtr their useless on 2wd cars

tho once its gone you find out fast how much of a pain it is to park such a big car in small carparks without 4ws

[derek burns]

m8 i had problems my hicas on my 33 gtr done the ignition test fluid level even changed the two springs of rear hicas above rear diff bla-bla- enyway it was the steering angle sensor on the s/wheel db1

[Cheyenne]

1. HICAS, my light was problematic and kept coming on so I was advised to reset the ECU (disconnect the battery), this solved it. Had checked power steering oil etc and all was fine. It has now been OK for the last year.

2. The oil guage probably needs a new sender unit. Had the same problem when I got my Skyline, the guage would just drop to zero on occasion and then rise back to the 4 mark suddenly. Put a new sender unit in and the guage has worked fine for the last 3 years.

[Jay]

Originally Posted by andybob

tho once its gone you find out fast how much of a pain it is to park such a big car in small carparks without 4ws

Erm, cough, HICAS isn`t active at low speed, so wouldnt make any difference to parking. Maybe your thinking of the sort of system they use on the Celica or Prelude

[conceptua tuning]

1/ what is HICAS and what does it mean as mine keeps poppin up on my dash when driving

HICAS is a computer operated rear wheel steering system.

It takes information from lateral G sensors, speed sensors, and steering wheel input sensors, i.e. how far you are turning the wheel.

The HICAS computer (below parcel shelf on an R33) uses the data to work out how best to rear wheel steer the car.

When you turn into a corner, the HICAS applies opposite lock to the rear wheel, i.e. turns opposite to the front steering input. It does this to increase the speed of turn in.

Once the car is in steady state cornering (when you are holding the steering wheel in a set angle) the HICAS then turns the rear wheel in the same direction as the fronts to add stability to the car under cornering.

Couple of things to bear in mind-

1. spirited drivers, and deffo drifters, may not like the HICAS interfering with their steering inputs...

2. at no time does the HICAS add more than 1 degree of steering angle to the rear wheels. Ever.

Furthermore-

ALL cars have rear wheel steering. The rubber bushes all deflect slightly under the forces of cornering.

For example, if you examine the multi link suspension on the Skyline this deflection will add various bending forces according to the grip of the tyre and the lateral loads of the wheel. As a consequence the steering angle will change according to the forces being transmitted through the various bushes...

The suspension designers use this to dial in changes in the geometry that will (or should!) assist grip under cornering. Polyurethane bushes are designed to minimise deflection under cornering to keep the geometry as the designers intented.

The easiest way to grasp how the wheel geometry changes under cornering is to think of the camber (I know we are talking about steering) of an outside wheel under cornering conditions.

The lateral forces created under cornering conditions manifest themselves by trying to push the wheel wide. This is countered by the grip of the wheel. This only happens at the bottom- the contact patch. The lateral force is transmitted to the wheel at axle height- where the wheel bolts to the hub.

As this force is higher than the contact patch the entire wheel is subject to a bending force which pushes the top of the wheel out by deflecting the rubber bushings, resulting in a camber loss, or more positive camber. This reduces the contact patch of the tyre (which should be as square to the ground as possible) and therefore reduces grip.

So you can see the cornering force changes the attitude of the wheel relative to the vehicle.

In addition the geometry changes also occur under braking and, in the driven wheels, acceleration.

Hope this helps!