Heavy Steering And Hicas Warning

[GTSBoy]

Crack and taco.  Coke & hookers?

[Missileman]

yup all of the above, typical friday arvo. if it is not his ecu it will be the speedo, mine did the same on a recent trip to nimbin, that road out of murwillumbah would have to one australias worst.

[glenndrayton]

Hi,

For anyone still interested in this, I had the same issue for the past four years on my 1994 R32 GT-R. The HICAS light would come on a few minutes after driving and the steering would go dead heavy.

I had Nissan and another workshop run the HICAS diagnostics multiple times - no problems: the back wheels did their flappy thing and everything.

Finally, just this week Custom Importz in Lonsdale SA found and fixed the problem. There were actually three faults:

1. The speed sensor in the back of the instrument cluster was faulty.

2. The steering angle sensor was faulty

3. (Not such an issue). One of the rear solenoids was faulty (this did show in up diagnostics but replacing it not fix the issue until the above two were fixed).

For anyone having this problem, follow the advice above to run the HICAS diagnostics, check fluid levels etc, but also get your shop to check these sensors in around the console and steering column. They were the "missing link" that did not show up in diagnostics.

Glenn

[niZmO_Man]

I hear clicking coming from the passenger (left) side tail light area, is there where the solenoid is?

[GTSBoy]

No, the HICAS solenoids are the big arse lumps just in front of the driver's side axle.  Hydraulic pipes coming down the chassis rail to them from the front, flexibles going out of them to the HICAS rack.  This image of an S13 shows it, correctly named, as the "fail-safe valve".

 

[GTSBoy]

And following up on Glenn's update......looks like Missileman was on the money with the speedo.

It will come to the point where we will need to look at wiring diagrams for non-HICAS Nissans of the era to work out how they ran their power steering assistance control without a HICAS computer, so we can delete the troublesome buggers of things when even the usual bypasses we do stop being good enough.

[glenndrayton]

Could well be. I had the same clicking noise and that was resolved. Best to ask your mechanic though.

[33SOM]

I'm trying to figure out why my steering is heavy at low speed.

So far I have figured out the speed out of my cluster is fluctuating around 10kmph or so (looking at the software on my link ecu) Also measuring the yellow/green wire at the Hicas ecu the volts are fluctuating at a constant speed.

Could this fluctuating be causing the hicas to stop adjusting the valve in the steering rack?

Glen did you have to replace the whole cluster or can the speed sender be replaced on it's own?

I tried many times to get the car to enter diagnostic mode but it wouldn't do it..

Cheers!

 

[GTSBoy]

The speed signal from the speedo head to the ECU and to the HICAS CU is a square wave 0-[something, I think 5] volt PWM signal.  You will see it vary under normal circumstances.  But I suppose the speedo head could fail in a way that the indicated speed is fixed, or never goes low enough to boost the assistance.

Look at the R32 GTR workshop manual pdf for guidance on how the AC speedo sensor signal is converted to the square wave signal and what you should see at various road speeds.  Then use a scan tool to interrogate the HICAS CU for what it's seeing.

[33SOM]

Thanks for the reply.

There is probably nothing wrong with my speed sensor (I just assumed that the reading fluctuating so much indicated a problem) and my Hicas issue is most likely something else. 

Cheers