I know, im asking too many questions, but i guess a new owner, i have to ask someone ha ha ha

 

 

My car feels fine, steering is same all way full lock to full lock,

But,

 

once the speed goes over around 40 to 50 the steering wheel slowly goes off center by about an eight of a turn to the left. Once the speed drops below about 40 it once again goes back to sitting at normal position.

 

I have a red hicas light, and once that lights up, the problem doesn't happen.

 

Now from my understanding hicas is the rear steering ? but i was told this was disconnected due to it being terrible, again not sure if that is true ?

 

how does this happen, and why and more important, how can i stop it please

Your tracking is out and/or the boss on the steering wheel might not be lined up. Check the fluid too, but sounds like the HICAS is trying to compensate for the misaligned geometry over 60kph. HICAS will adjust the rear wheels to try and compensate and this has an effect on how the car points and thus, will throw the front wheels off line. In effect, the car will be 'crabbing' lightly at that point.

can never ask too many questions...

 

Are you saying the hicas light is on all the time? Or at random? Sounds a bit like the system has been disabled but not locked off??!

 

Check your tyre wear!

 

Other than that its perhaps somthing to do with the variable power steering on them but i wouldnt really know without seeing it do it!

Si, Hicas is inactive between 20mph and 80mph i believe...

funny you mention the wheel, there is an after market wheel on it, does the centre need to be moved then maybe?

 

I have checked the power steering fluid, and while it needed a small top up, it was not a vast amount.

 

Can i check these items myself? and where do i find the bits to check

 

 

thanks for the very quick replies too, its so good to get help like this

sorry, forgot to add. the light is NOT on all the time, only over a certain speed, but unsure what it is i think about 80 ish

Si, Hicas is inactive between 20mph and 80mph i believe...

 

 

Where did you hear that? It's a high speed system and switches on at about 60kph+

Si, Hicas is inactive between 20mph and 80mph i believe...

 

Nope...in fact the speed settings are different for UK and Jap, but that speed region is definatly active, I cant remember exact figures, but its almost the opposite to that (ie only active beteen 20-80.....more like 40-100 I think...will have to check...)...

Nope...in fact the speed settings are different for UK and Jap, but that speed region is definatly active, I cant remember exact figures, but its almost the opposite to that (ie only active beteen 20-80.....more like 40-100 I think...will have to check...)...

 

It works at faster speeds than that I think Dave. I believe Nissan testers found it at most benefit at speeds of over 120mph.

It works at faster speeds than that I think Dave. I believe Nissan testers found it at most benefit at speeds of over 120mph.

 

UK yes (I think), Jap no.

mine is a jap, not got the bottle to try 120 yet though

UK yes (I think), Jap no.

 

Just found this on Gio's site. Seems to confirm what I remembered anyway.

 

Apparently not. JDM too. It's just their speed limiters are set to 114mph. System carries on worring at similar ratios once ECU has been de-limitered.

 

http://www.300zxtt.co.uk/hicas.html

funny you mention the wheel, there is an after market wheel on it, does the centre need to be moved then maybe?

 

 

Check it has a HICAS compatible boss first. If it has, make sure it's lined up correctly.

thanks for the help funky, how can i tell if it is compatible ?

Just found this on Gio's site. Seems to confirm what I remembered anyway.

 

Apparently not. JDM too. It's just their speed limiters are set to 114mph. System carries on worring at similar ratios once ECU has been de-limitered.

 

http://www.300zxtt.co.uk/hicas.html

 

Yes I have that book, however its always been said that the Uk (and presumably US) had higher speed hicas settings than the Jap version though...although I cant actually find any official proof of this

IIRC, there's a small cutout at the bottom of the boss that locates over a lug. You need to make sure that the boss is fitted in relation to the lug. If it's moved or not lined up, it's that which knocks the hicas geometry out once HICAS becomes active.

Where did you hear that? It's a high speed system and switches on at about 60kph+

 

 

To be honest i really cant quite remember! Im just sure i remember reading somewhere that between 0 and 20 mph in turns opposite to the front wheels and above 80mph turns the same way "to aid high speed lane changing" i distinctly remember that line.....

 

I have a feeling its in my UK spec manual.... but perhaps not. I'll have a look tomorrow!

HICAS was not designed for manouver. Mearly as a basic stability aid.

Yes I have that book, however its always been said that the Uk (and presumably US) had higher speed hicas settings than the Jap version though...although I cant actually find any official proof of this

 

Interesting. I was always under the impression that the US spec has a quicker rack and that was it. I'll do some research. :)

there is a small cut out, and there seems to be an electrical plug which goes to the horn poking through it. the cut out when the wheel is straight, is to the bottom left if your looking at the boss as a clock, it is in the 7 position

 

 

feel like im learning something here ha ha ha

If you're interested in reading further, I found this on TT.net just has some information on HICAS and aftermarket steering wheels.

 

http://www.twinturbo.net/net/viewmsg.aspx?forum=general&msg_id=1402944&forum=general&dtSearch=4

so i need to check the back of my boss, and if it doesnt have them gold rings, i need a new one then ?

 

i couldnt see the back earlier, but from the front of it, i dont think it has.

 

having said that, the steering doesnt always go out, so that kind of makes me question it a little?

sorry to hijack.. but my back end seems to "wobble" at any speed, was striping down the dash a few weeks ago and found the hicas bit stuck under there.... is thats whats making it wobble or is it something else?

 

Sorry again!