A problem I've had for some time as originally my geometry was completely on the cock and the HICAS boss was out of alignment. After rebuilding the suspension, set the dead-ahead position in relation to the tab at the top of the HICAS boss.

 

Then, had all the geometry set. Drives perfectly, except when you accelerate quickly and the wheel then turns off centre. After a while (about 5 - 10 mins of driving), the HICAS light comes back on and the problem goes away.

 

What I can't understand is; why, after setting everything up, does it still do this? The car drives perfectly and the geometry is set up correctly.

you'd be best off getting rid of the hicas TBO Si, get a lock out bar

I've no idea of the issue but if you are wanting the stiffness of up rated anti roll bars then a Hicas iliminator might be the way to go.

Hi Si,

 

I'm no expert on the HICAS system but have you got an aftermarket steeringwheel fitted with a HICAS enabled boss? Only reason I ask is that I've seen one previous example where an incorrectly aligned steeringwheel boss caused the HICAS system to go beserk. If memory serves me the issue with that particular car was that the two HICAS discs in the boss were not aligned properly with the steering wheel in the "dead ahead" position. This caused the sensor the constantly read that the steering wheel was off-centre by a few degrees and consequently activated the rear steering. However, the HICAS ECU is intelligent enough to know when there is a problem and after a few minutes of reading this incorrect angle it lights up the HICAS warning light and disables the HICAS (until the next startup). This may be what is causing the problem with your setup. You may want to send Eric (aka Lymon) a PM and ask him as he's very well versed with the HICAS system. Alternatively, get the car on a ConZult and do a HICAS diagnostic. If you've got your steetingwheel centred the diagnostic screen should indicate a steering angle of 0 - any other reading indicates the steering wheel and/or HICAS plates in the boss may require aligning.

 

HTH

 

All the best,

 

Dan

Hi Si,

 

I'm no expert on the HICAS system but have you got an aftermarket steeringwheel fitted with a HICAS enabled boss? Only reason I ask is that I've seen one previous example where an incorrectly aligned steeringwheel boss caused the HICAS system to go beserk. If memory serves me the issue with that particular car was that the two HICAS discs in the boss were not aligned properly with the steering wheel in the "dead ahead" position. This caused the sensor the constantly read that the steering wheel was off-centre by a few degrees and consequently activated the rear steering. However, the HICAS ECU is intelligent enough to know when there is a problem and after a few minutes of reading this incorrect angle it lights up the HICAS warning light and disables the HICAS (until the next startup). This may be what is causing the problem with your setup. You may want to send Eric (aka Lymon) a PM and ask him as he's very well versed with the HICAS system. Alternatively, get the car on a ConZult and do a HICAS diagnostic. If you've got your steetingwheel centred the diagnostic screen should indicate a steering angle of 0 - any other reading indicates the steering wheel and/or HICAS plates in the boss may require aligning.

 

HTH

 

All the best,

 

Dan

 

I had the exact same problem with my HICAS when I changed to an aftermarket steering wheel. It became a real pain to sort, so in the end I just binned it and bought one of Dan's eliminator bars :)

Yes Danny, I have the HICAS boss, hence why I said that I’d just re-aligned it. ;)

 

The system was fine when I first bought the car, I’ve not changed anything on the steering wheel side of things. The HICAS boss needs the tab aligned with top dead centre which mine now is.

 

I have thought about eliminating it, but I really want to keep everything that was fitted to the car, in full working order.

Has the car always done it then si?

No it hasn't. The column was disconnected from the rack about a year and a half ago and I was running around in it with the boss off centre. It was put back to original settings by myself and Jimmer 2 weeks ago. Steering dead ahead with tab at top, then geometry set around that. So, the HICAS boss is top dead centre as it should be and the geometry is set up around that.

Well if it aint the boss, youll just have to work your way through the HICAS system. maybe one of the solenoids is fubar'd or one of the hicas arms???

 

Sorry but i know sweet FA about what parts form up the HICAS system

how is the dead ahead setup with regards to zero steering angle? can it be a turn or 2 out when you set it up or does it reset after every shutdown startup? maybe get it on jimmers conzult if that gives you steering angle just to be sure everything is hunky doorey?

You may want to send Eric (aka Lymon) a PM and ask him as he's very well versed with the HICAS system.

 

Youd have a job, i think he was downgraded to registered user during the re subscription blitz so now he wont be able to send or revieve pms, as his self appointed pa i tried to get his "honory member" status re instated but to no avail!!

I dony know alot on the hicas system other than the fact that the z32 uses the same rear steering arm as they use on the front of a:x::x::x::x::x:

 

Heres the link to the TTZD tech page on hicas, could be worth a go http://www.ttzd.com/tech/hicas/hicas.html

ConZult is the first step without a doubt ;)

I have a similar issue, whereby the car slightly steers under heavy acceleration. I'm convinced that one of the subframe bushes needs to be replaced and that the HICAS is fine. Are your bushes new?

Cheers for the link and info guys.

 

I have a similar issue, whereby the car slightly steers under heavy acceleration. I'm convinced that one of the subframe bushes needs to be replaced and that the HICAS is fine. Are your bushes new?

 

I have subframe locking collars! LOL

>> Then, had all the geometry set. Drives perfectly, except when you accelerate quickly and the wheel then turns off centre. After a while (about 5 - 10 mins of driving), the HICAS light comes back on and the problem goes away.

 

this usually indicates a problem with the steering wheel sensor.

either sensor offset is wrong or sensor has failed.

Other possibilities could be air in the HICAS system.

(the procedure on how to bleed the system is in the service manual)

or a problem with the steering rack bushings:

if these have failed it can cause the steering rack to move freely, which can cause the steering wheel to go off center and cause the HICAS to go into failure mode.

 

-Eric

Well, the steering rack bushes are new PU ones. Sensor offset should be ok, so I guess it's either the sensor that's at fault or the air in the system?