R32 GT-R HICAS light on, only after 30+km on highway?

[gtrbubba]

Have a weird one here; on the way to the track (Calabogie), the HICAS light came on after about 35km of steady-state highway driving.

When the car was restarted for track sessions the light was out, and after five lapping sessions (about 75km in total) the light never came on.

On the way home, again after about 30+ km the light came back on!


Any ideas what would trigger the HICAS light on long(er) trips?


Addendum: I do have an aftermarket "rev-meter", whose primary purpose is to get around the 180km/hr limiter. I did move the cables around a bit for it before the trackday, so maybe I don't have a good connection for the ECU speed sensor circuit. (the device is spliced into the ECU speed sensor circuit so it can "fake" speeds above 180...)

[Spencer87]

I had mine only come on after 10-15km of hwy driving (hovering around 120km/h). At the time, I thought it was because of my aftermarket steering wheel (apparently theres a controller that you need to get or something), but nothing changed and it stopped about two months ago

[gtrbubba]

With respect to the error reporting, is it the last fault recorded, or does the system need to be currently faulty to report a code? (light on)

Also, if the light is off while driving, does that imply that all is (currently) well with the HICAS system?


Hmmm....

[Spencer87]

I cant remember the details, but I remember reading something here or on Wiki.

http://www.skyline-owners-club.com/f...yline_book.pdf (our link died for some reason and the thread is closed).

[bellis_GTR]

mine does this as well. I thought it was because my alignment was off.

[NeptuneGTR]

Isnt it that the ecu sences that its highway driving, im perrty sure its just goes it to highway mode, Its normal.

[Nismo_line]

mine does that some times too but i have no hicas pump

[NeptuneGTR]

The first time it happend to me I freaked out, i though something was really wrong.

[DarkCaporaL]

Isnt it that the ecu sences that its highway driving, im perrty sure its just goes it to highway mode, Its normal.

Huh? I don't think there's such a thing as "highway mode"...lol

If the light is on, then something is wrong. The ECU should throw you a code.

And bubba, I think the light as to be on for the ECU to throw you a code, meaning you have to check it when the fault happens. (but don't quote me on this, I've never tried it, just something I vaguely remember reading).

If you're HICAS system is locked/not entirely there (like foxracing), then its normal that the ECU throws you an error after a while. I have a lock bar and I get a code after a few kms of highway driving because whoever locked it did not bypass the light/cut the wire, and I'm too lazy to do it (the light doesn't bother me that much).

Since HICAS only activates at 80+ km/h, if you're only city driving you would not notice an issue. That's why the error happens after a couple kms of highway driving.

[gtrbubba]

...Since HICAS only activates at 80+ km/h, if you're only city driving you would not notice an issue. That's why the error happens after a couple kms of highway driving.

That really doesn't explain why there was no HICAS fault light in a series of 15+ minutes track sessions after arriving at the track! FYI, a 5-lap session at Calabogie is almost 30km, and about 15 minutes at a "casual" pace. I'm pretty sure my first session was about 7 laps, or about 40km.


Either the HICAS ECU does a system poll after a significant delay, or there's something else at play here with respect to high(er) speed steady-state driving and the HICAS ECU fault checking routines. (it seems that others have experienced the light only after a duration of highway driving as well...)

FYI, in my case in both directions (to/from the track), the delay 'till the light came on was about 20 minutes.


I'm also assuming that if the system was really borked, it should throw the code the first time it tries to activate. (ie, the second corner at Calabogie!)


Hmmmmm...

[1991HCR32]

I heard HICAS light comes on possible because of low powerstering fluid

[DarkCaporaL]

If it was low powersteering, then it would be on all the time. When it starts to get low you can actually see it flicker when you hit bumps / corner hard, like the hand brake light for brake fluid.

Maybe you didn't get the error at the track because you're constantly accelerating / decelerating? (unless the track is all +80 km/h even curbs)

All I can say is that my HICAS light also only comes on after a few kms of highway driving (only when I cruise at a speed of over 80 km/h for a while). If I do multiple accelerations / decelerations going above and under 80+ km/h, it will never come on. It only if I cruise over 80 km/h for a while. But my system has a lock bar, it's not really a good reference, except maybe showing that it takes a while for the ECU to respond?

[TorqueSplit]

Hey Guys, I know this is an old thread, but I am experiencing the same problem with my HICAS light coming on a few km's down the road...

I have a theory on what may be causing this. So I wanted to share it with the community.

First, everyone who suggests to check the power steering fluid in both the hood and trunk reservoirs is of course correct. The next thing to check is the alignment and the "steering angle sensor". A couple of years ago, my HICAS light would come on if my car was out of alignment. So I got my car aligned and that took care of the problem. Then about 2 years later, the same problem happened again after an engine swap (and we put the engine in from the underneath-so my alignment and steering column were out of spec.). This time the light came on before and after I got it aligned. So I'm looking at good fluid level's and good "physical" alignment. This leads me to think the steering angle sensor is sending data to the HICAS computer that is causing the light to come on. To test this theory, I purchased the NISSAN DATASCAN software for like $50.00 and it has a nice HICAS diagnostic tab on the screen. And it shows my steering angle is reading 220 degrees even though my wheels were straight (which should be zero degrees)! So what I think might be happening is that the car thinks it's turning when in fact it is going straight. So the steering column sensor isn't in synch with the angle of the front wheels. I don't know if this is definitely going to be the cause, but that seems very logical to me. It's basically the same condition as my car being out of alignment, only this time it's out of alignment only logically and not physically - if that makes sense.

I'll update more after I get the steering wheel and wheels in synch with each other. I'm gonna buy tie rod ends and ball joints at the same time I fix this so it might be a couple of weeks guys. Stay tuned. (No pun intended).

Oh - and the NISSAN DATASCAN software also shows the voltages of the front and rear solenoids-which is really cool even though I'm not sure how to use that data yet! If anyone would like a screen shot of how this software works on the HICAS tab, hit me up and you'll be able to see how it's working for me. OH and another thing - I think I understand the mysterious clutch sensor question too (It is also part of the HICAS data)! I think the clutch being depressed or not switches the HICAS system into Heavy or Light Steering. This might be to compensate for the driver's body movement while shifting. That is just another theory though. But I don't think it has anything to do with preventing the vehicle from starting, that's for sure. This post is all for R32's with OEM steering wheel as well, so I'm sorry for not having any info on R33's or newer.

[NismoS-tune]

I had a light come on. And hour later, HICAS is gone, the car is lighter and I get more corner feel, all that without scratching my head to troubleshoot the sketchy crap