Heavy Steering And Hicas Warning

[glenndrayton]

<p>Hi,</p>

<p>My 1994 R32 GT-R has two possibly related problems. After driving for about five minutes the power steering basically shuts down and the steering is heavy as if it has no assistance, at about the same time the HICAS light comes on.</p>

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<p>The power steering fluid level is normal as is the reservoir in the boot. My mechanic says the power steering pump is not showing any obvious signs of problems and the car is genuine low mileage and generally mechanically excellent.</p>

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<p>Any suggestions, before I take this to Nissan?</p>

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<p>Note that the steering returns to normal when you switch the car off and start again though I have not worked out how long it takes to "reset".</p>

[White GTS-T]

Does your speedo work? A broken speedo cable will give the aforementioned problems and is a common point for failure on R32's.

[GTSBoy]

Put the HICAS system into self diagnostic mode and look for error codes. Google how to do it.

If it won't go, or you get nothing useful, get your (or another) mechanic to put a proper scan tool onto the Consult port and read the HICAS CU's state of happiness.

[I gotta R34gtr v-spec]

Similiar problem with my 33, it could be the g-sensor under the center console,or the capacitors in the hicas computer, because of there age they start leaking fluid.i replaced the g-sensor with a digital one from nengun about $500 and had the local tv repair man replace the capacitors in the computer for about $70.

[glenndrayton]

_{speedo works fine. Will try the HICAS debug mode and report back. Thanks.}

[89CAL]

Aftermarket steering wheel and boss kit? Check the boss kit is fine

Can be a number of things but Mine did this when driving for a short while the power steering would go and the HICAS light would come on

[Aazzy]

Had the exact issue with my 33. Hicas computer faulty. Picked up a second hand one for $50. I was able to swap it with a friends 33 just to be certain before I replaced it.

Edited July 26, 2014 by Aazzy

[glenndrayton]

Hi. Car had a aftermarket steering wheel, but I swapped it for a stock one. The problem remained.

Just tried several times to invoke HICAS diagnostics mode but it just won't play ball. I guess this might indicate a faulty HICAS computer as mentioned in above posts?

[GTSBoy]

Maybe. Nut that's why I suggested if you fail at getting it into diag mode on your own that you use a proper scan tool. The method for getting it into diag mode relies on various inputs still working (steering angle sensor, brake signal, vss, etc). If one of those is faulty then you can't get into diag mode to find out that it is faulty.

[glenndrayton]

By "proper scan tool" you mean something that any Nissan workshop would have or are these some more specialised? Anyone in Adelaide want to recommend the best mechanic/workshop or Nissan service centre to work on this problem? I've had other work done at Main North Nissan, but they don't seem that good e.g. didn't know how to adjust the air/fuel mixture on a Datsun 280ZX!

[niZmO_Man]

The reservior in the boot is for ATTESA not HICAS. Also the G sensor isn't used by HICAS AFAIK (R32 remember).

Most likely the computer under the boot. Unplug the smaller plug (there are two) and see how you go. The computer is located on the driver's side, under the parcel shelf.

The manual steps to invoke the diag mode is a pain, it took me a few tries to get it working.

[GTSBoy]

By "proper scan tool" you mean something that any Nissan workshop would have or are these some more specialised? Anyone in Adelaide want to recommend the best mechanic/workshop or Nissan service centre to work on this problem? I've had other work done at Main North Nissan, but they don't seem that good e.g. didn't know how to adjust the air/fuel mixture on a Datsun 280ZX!

Brenton @ Foursnmore in Pooraka has a scan tool that I have put onto my car and seen every computer come up for diagnostics (granted, that's only the ECU and the HICAS these days...not having TCU or ABS modules in the car reduces the possible number you can see!). And also on things like auto Legnums I've seen the ECU, TCU, ABS, etc all come up and drop their pants for inspection. So much easier than trying to make diagnostics happen manually.

[glenndrayton]

An update on this. Main North Nissan sent the car to Clisby who took the HICAS ECU apart and cleaned it up a bit, but still faulty. I'd like to track down another ECU but the ones on ebay have quite different part numbers. My has part number 28505 12U00 and serial 4623. I can't find anything like this. Would a ECU with number 28505 04U00 work? Does anyone know how to interpret these part numbers? Was my 1994 unique in having this HICAS ECU part number?

[89CAL]

you need 28505 04U60

[glenndrayton]

Only one I can get hold of is 28505 04U50. Will have to try that.

[89CAL]

Should be right. Will just be out of a 90 model GTR most likely

[glenndrayton]

Update on this for anyone interested. I've owned the car a few years now and still no resolution to this issue. Within a few minutes of switching the car on I get zero power steering, followed a few minutes later by the HICAS light coming on. I know the HICAS is all working (passes all diagnostics) so this continues to be a mystery of the Universe, right up there with Dark Energy and Dark Matter. I'm calling this Dark Power Steering Failure.

[niZmO_Man]

Have you tried unplugging the smaller of the two plugs on the HICAS controller/computer box?

[Missileman]

If you have eliminated the hicas ecu as the issue, then you can try removing the cluster and have a good look at that, you will need to take it right apart and examine where the taco mechanism seats into the cluster. What you are looking for, is a small electrical plug that takes the rpm signal from taco and joins it to the rest of the clusters wiring. Carefully clean the contacts and make sure the plug is seated correctly when you reassemble. While you have the cluster out, make sure you clean (very carefully), all those annoying cooper trace connecting wires at the back of the cluster, and be very careful with the end of the taco cable too.

 

 

[Missileman]

In the above comment I have mistakenly written taco when I should have said speedo, Too much crack last night;)