Hicas light with heavy steering R33

[RSi]

Wider tires will freak out the hicas.

Thats what happened to mine, thus the lockout bar...

[zeldaman]

Hey ill kick in my 2 bits... so i put 18x10" rims on my GTS and with in probably a week my hicas gave up the ghost. So out came the hicas system all the way down to dysassembling the PS pump and removing the blades of the rear impeller so as to keep it from building pressure, blocking the line off, removing all the lines etc. TOTALLY removed. I still have odd steering issues. goes heavy randomly... cant seem to fix. about to try changing out hicas ecu and maybereplace solenoid. best of luck but i doubt removing it will fix it full time.

[Skym]

Heavy steering = HICAS ECU in limp mode.

Sometimes HICAS ECU has bad solders inside. I encountered this problem on my cars HICAS ECU when steering went heavy. Also had water entering breathing holes on HICAS due to trunk lid wasn't closed properly and resulted in damaging HICAS ECU. I ended up changing HICAS ECU and flipping it upside down, so breather holes faced downwards.

In think in other cases it might be a faulty steering angle, etc sensor. Removing HICAS solenoid in engine bay, bypassing hoses to HICAS solenoid, so they loop and earthing loom to HICAS solenoid solves the HICAS ECU problem.

[Daryl @ RightDrive]

Skym has some very good advice, also, from my own experience, make sure nothing is hitting the HICAS ECU in the trunk. I had my HICAS go crazy after a tire iron propped up against it and was banging on it.

[kengeroo]

On a 95 R33 GTR
how will a missing steering wheel angle sensor affect the performance of the HICAS system ????
the light does come on after a few minutes of highway driving.

please and thank you.

[MattiasJacobs]

Check power steering sensor in hardline on turbo side i think? Mine does this same thing but i took my hicas light right out lol.

[Skym]

As far as I know it's the HICAS solenoid in engine bay (next to / just behind battery) that can affect powersteering weight, movement of HICAS rack on R32. It's controlled by the HICAS ECU.

It might affect front steering rack as well, as powersteering pump is a dual stage pump (HICAS pump in rear of powersteering pump and front powersteering pump in front of powersteering pump). So both front and rear racks probably would be affected at the same time.

R33 powersteering pump is a single stage powersteering pump, so front powersteering rack is affected, not HICAS rack in the rear. R33 has a separate HICAS system in the rear that can be disabled electronically and via HICAS lockbar.

On more investigation into how HICAS works, the valve next to / just behind battery on R32 is a pressure valve and looks to affect rear HICAS steering rack only on a R32. Also there's a lockout valve next to driver side rear wheel.

I found out HICAS ECU reduces assistance to front powersteering rack via another valve just under where steering wheel connects to front powersteering rack. When there's a HICAS sensor, alternator, etc problem, HICAS ECU adjust's that valve on front powersteering rack to give a similar amount of assistance it gives to powersteering rack at 175-200km/h.

With removing HICAS and earthing out the sensors, etc to ECU via Tomei lock out kit, it might work to turn sensor, etc error code off on HICAS ECU and restore assistance to front powersteering rack. This valve on front powersteering rack is on both R32, R33 HICAS front powersteering racks and would explain the heavy steering problem (less assistance).

HICAS ECU via that valve on front powersteering rack gives max amount of assistance at low speeds and less assistance as speed increases.