HICAS light comes on when driving at a constant speed over 100km.

[CONAN]

As the topic says, what could be the problem guys?

It always happens when i drive on the highway (M5).

It never happened before. I just changed my 2 front tyres and its only just come on after i did that. The cars an r34 gt-t.

Any help will be appreciated.

[MegaGTS4]

Tyres different rotational circumference to the rear tyres, or the steering wheel sensor (behind steering wheel) needs realigning.

(EDIT: the differance in Tyre profile will only affect vehicles with ABS and Attessa and won't affect those with Hicas as it get its speed reading from the gearbox)

MEGA

[CONAN]

Thanks for your help Mega.

The 2 front tyres that I changed are still the same size as my last 2 front tyres though, and the HICAS never appeared back thenso i dont think that could be the problem or could it? My front tyres are 225's and my rears are 265's.

Though i think it could be the steering wheel sensor that you speak of, since my mechanic did have to open up my steering wheel the other day.

Is it an easy job to realign the steering wheel sensor?

If so can you tell me what i need to do or should i just take it to a workshop?

Regards

[MegaGTS4]

Its not the 225 or the 265, its the profile which will be 50, 55 or 65 etc that I was refering too though. (although this seems to affect vehicles equiped with attessa more than ones with hicas though, sorry my bad!)

But if your mechanic removed the steering wheel then he must have done a wheel alignment and straightened the steering wheel by removing it and changing the position on the spline, this will be fine on any other car but not on one with hicas, the poor car thinks its going round in circles hence the error code.

As for fixing it, maybe do a search as it has been covered before with pictures and descriptions on how to realign.

[CONAN]

It could be a change in the size of the tyre's profile.

How can i fix that problem?

Regards

[ylwgtr2]

do a diagnosis check....the plug on the 34 is in the panel below the steering column

[MegaGTS4]

There is no easy fix if its the tyre profile as the car will be getting two different speed sensor readings from the front to the back, so basically need to change the tyres to the same profile as the back to remove the error in the system. Hicas has two speed settings fast and slow, and this changes the system to suit fast corners or slow ones, if there is a marginal differance between the two speed sensors (front/back) it will shut down hicas.

MEGA

[NismoGirl]

Ok. I have this problem like this. Could just be conincidental that it's happened when you changed the tyres.

This is the problem I have with my hicas. If I drive on the M1 (Brisbane - Gold Coast) to about the Strawberry Farm half way down the coast (say 30/40ks?) the light comes on.

I've had heaps of problems with my hicas since purchasing the car. Once it was realised that there were wires disconnected, it was all fixed. Then driving up to the sunny coast one night the light came back on. I was fuming.

Ended up getting the car put onto the diagnostics machine and it said that there was a fault in the sensor in the steering wheel.

Basically to put it simply, there is a sensor in the steering wheel that can loose contact sometimes. This happens if the wheel is held straight or moved slightly for a long period. I was told this sensor was about $300 to fix but seeming it only happens on the highway (when hicas comes into effect) I didn't bother getting it fixed because I dont personally do highspeed lane changes and drastic steering movements on a straight road.

If you can, try and get someone to plug your car into a consult machine and get a report printed out on what fault is coming up in the diagnostics.

[ylwgtr2]

you dont need the consult machine to find it....i had an airbag problem that consult couldnt detect....run the on board check and back probe the wires in the system.

[NismoGirl]

do a diagnosis check....the plug on the 34 is in the panel below the steering column

Right...

Ok. I was just suggesting that this was one option and this was the way I found my fault.

[MegaGTS4]

Ylwgtr2 is right the chances that someone has the consult is slim, on board diagnostics is the best way and its free too.

Nothing is this conincidental if your playing with the steering wheel position as is the things the hicas rely on. The speed sensor and the steering angle sensor are the eyes and ears of the hicas system.

MEGA

[Lepperfish]

Think it happens on most GTST's.....

[Baroo]

If it is the same problem as the Z32 i've got then it could most likely be the hicas system acting on its own due to something being aligned incorrectly as my steering is slightly to the left when i travel along highways the hicas thinks i'm constantly turning and it recognises this and turns itself off. Therefore basically /hopefully all u need to do is fix whatever is causing this.

[MegaGTS4]

Sorry Conan I have led you down the garden path, the steering angle sensor is out or not working properly because the only thing that works off the individual wheel speed sensors is the ABS system and attessa equiped vehicles (GTR's and GTS4's) and yours being a R34 GT-T it will be the sensor behind the steerig wheel that is out of alignment.

The hicas system gets its speed reading from the gearbox and this won't change no matter what profile tyre you use.

Take it back to the mechanic to fix it or ask him if he moved the position of the steering wheel, if he has tell him it needs to be aligned or put back to neutral position.

I hope you see this before you change try and change tyres.

Sorry if I caused any trouble again!

MEGA

[CONAN]

Thanks MEGA!, Im going to follow your advice by going back to my mechanic tomorrow to tell him to align the wheel back to its neutral position as you suggested.

Thanks for your advice everyone, I appreaciate it.

[OMRAN]

Sorry Conan I have led you down the garden path, the steering angle sensor is out or not working properly because the only thing that works off the individual wheel speed sensors is the ABS system and attessa equiped vehicles (GTR's and GTS4's) and yours being a R34 GT-T it will be the sensor behind the steerig wheel that is out of alignment.

as Mega said .... its the sensor ... (100%)

i have the same problem ... with my R34 GT-T .. its still there .. coz my car is converted to ( left hand ) and the steering box am using now is for nissan maxima ... which has no sensor ...

so .. the hicas coms out on highways ... only ..

check u'r sensor ... if its pluged ... or if somthin wrong with it ... ( hope its only unpluged )

good luck ...

[CONAN]

Thanks OMRAN.

But will it be of any risk if i dont get the sensor fixed?

Can HICAS screw me up if i constantly drive on the high way?

[MegaGTS4]

Thanks OMRAN.

But will it be of any risk if i dont get the sensor fixed?

Can HICAS screw me up if i constantly drive on the high way?

No it wont harm/risk anything as all it does is disables the hicas system and stores an error code for consult or diagnostics to retreive at a later date, which means that after 100 your car will act like a normal car that has 2 wheel steering.

I have attached some pics to help you understand the hicas system a bit better, you might find them interesting. (though they are for nissan's turbo Z they are the same in principle)

MEGA

[OMRAN]

Thanks OMRAN.

But will it be of any risk if i dont get the sensor fixed?

Can HICAS screw me up if i constantly drive on the high way?

i think .. u can read what MegaGTS4 have posted .... .. i think he have more experiance in hicas ... then me ..

and .. what i know .. is that it wont f*&^ up u'r hicas ....

and as Mega said ... u will be driving with 2 wheel steering ... ( thats am not sure about ... )

i'll try to see it my self .... if the hicas light go's on .. i'll stop the car .. and move the steering all the way ... right .. to .. left ... and look at the rear wheel .. if it start moving or not ... ( its a slight move .. 4 degrees only )

thanx alot MEGA ... u'v been helpfull .. ..