My Power Steerings Gone After Installing Hicas Lock Bar

[T04GTR]

if you reallllllly want to piss the hicas and alll the wiring. just go to dick smith and but a 12 volt inverter thingy. thats does 3,6,9,12volt. and just hard wire it in and hook it up to the solindoid to give you more power steering.

[Shaun]

Hi all,

I installed a lock bar on my R32 gtst and removed ALL of the unneccessary plumbing to the rear of the car and to the rear section of the PS pump (i removed the little impellers of the rear pump too). I didnt touch the HICAS controller under the parcel shelf though, but i still lost my power steering. The only electrical thing that i can remember was like a cast junction thing near the rear steering rack.

Any ideas anyone??

[heller44]

I do apologise for bringing a long gone thread back again, but thought that this might be the most appropriate place.

Finally been bothered to fix the power steering / hicas problem with my car.. took me a bit to find it but simple really.

Never had hicas working properly with my car, always goes into a failsafe condition (heavy). Thought it might have been due to the broken speedo cable that I repaired with a dab of devcon one day.. No such luck.

Seems that it was due to the late series 32 gtr dash that had been fitted. The pinout for the connectors on the back of the cluster differs, at least from the new gtr cluster, to both my old gts4 dash and the r32 wiring schematics that I have..

Bought the car and it was missing most gauges except for speedo and fuel. Warning lights on.. not oil pressure .. but hicas, 4wd, abs, headlight high beam indicator on when lights were turned off, indicator signals not correct either.

Managed to sort out where everything should go from comparing the circuits on each cluster.

Unfortunately I neglected to chase further into the speed sensor circuit on the cluster. The old dash just had what appears to be a switch, not much else.. The new dash has a zener diode across the pins for the sensor.

I had the polarity reversed on the wires.. all but about 0.6v of the signal being generated was being shunted back to earth..

Swapped pins over and sweet.

Hope this helps anyone.

James.

[Lozzzah]

Sorry just trying to understand this a bit better. The duty cycle remains the same (1230Hz) and the only thing that changes is the voltage which is across the Y axes? Max voltage being 6V and min being 0?

[GTSBoy]

Just download the R32 GTR workshop manual and look in there.  Lovely explanatory diagrams.

[heller44]

What he said.

If you really want to dig into it, its 123Hz approximately. Not 1230. Not duty cycle, frequency. Roughly inverse relationship to speed. 12v switched. 

If you don't know the difference, perhaps this isn't your thing?

Pretty sure there is a plug in module available these days for fixing things when hicas is locked out.

[Lozzzah]

Alright thanks. I’m just trying to remove the heavy steering for now till I have enough to get a non hicas rack. I’ve been told I could run a step down transformer to it but I don’t really want to burn out the solenoid.

I have a little bit of electrical knowlage so I understand roughly what is happening. I just  want to make sure I’m doing the right thing. I’ve just heard so many different things that I’m starting to get slightly confused now haha. 

Cheers for the help though guys!

Edited August 9, 2018 by Lozzzah

[GTSBoy]

I don't think a "non-HICAS" rack is the answer.  I'd be pretty sure that all that is happening is that the HICAS computer is doing what some other power steering module does in non-HICAS Nissans of the same era.  They all had variable assistance power steering, implying that they all had PWM modulated solenoids on them.  I have long thought that the answer to "fixing" these problems in our cars would be to look at Maximas or other shitters from the period and work out how they managed the assistance modulation, then find one of those boxes and wire it in in place of the HICAS box.

Granted, these days, it is probably a perfect use of arduino stuff.  Just pick up the speed signal off the back of the dash, maybe watch a few other inputs if you can be bothered, and simply write a program to run the solenoid accordingly.  More assistance at low speed, less assistance at high speed.