Jump to content
SAU Community

Recommended Posts

It's not OBD1. It's Nissan Consult. Their own protocol. It's easily readable with any workshop grade diagnostic handset that has Nissan config files. I did it (for HICAS diagnosis) with a generic workshop handheld on my car back in about 2000, immediately before I rendered HICAS unable to f**k with me any more.

And 10 years after that I ripped out every single HICAS related thing in the car, except the CU (which is needed to keep the power steering happy).

HICAS is the devil. It is made to make 7/10ths drivers look like 9/10ths drivers. But if you drive the car harder than 7/10ths, it actively tries to kill you. It is too stupid to handle real driving.

HICAS is also very hard to diagnose, because from what I can tell, the CU rapidly forgets codes if the initiating failure does not stay present. So you can really only diagnose it while it is in the process of losing its mind.

'twere I you, I would put a HICAS delete kit on the car. With decent upgrades to suspension arms/bushes, tyres and a wheel alignment, the car will turn in 11ty times better than the apparent improvement given by HICAS back in the dim nostalgia days of the late 80s.

  • Like 1
8 minutes ago, GTSBoy said:

It's not OBD1. It's Nissan Consult. Their own protocol. It's easily readable with any workshop grade diagnostic handset that has Nissan config files. I did it (for HICAS diagnosis) with a generic workshop handheld on my car back in about 2000, immediately before I rendered HICAS unable to f**k with me any more.

And 10 years after that I ripped out every single HICAS related thing in the car, except the CU (which is needed to keep the power steering happy).

HICAS is the devil. It is made to make 7/10ths drivers look like 9/10ths drivers. But if you drive the car harder than 7/10ths, it actively tries to kill you. It is too stupid to handle real driving.

HICAS is also very hard to diagnose, because from what I can tell, the CU rapidly forgets codes if the initiating failure does not stay present. So you can really only diagnose it while it is in the process of losing its mind.

'twere I you, I would put a HICAS delete kit on the car. With decent upgrades to suspension arms/bushes, tyres and a wheel alignment, the car will turn in 11ty times better than the apparent improvement given by HICAS back in the dim nostalgia days of the late 80s.

im in agreeance with you there, Im actively looking at the different kits and what all is into locking it out and getting rid of the light aside from unplugging the bugger. I see tomei has a kit that you can basically falsify the A-OKAY  report back to the ECU, and uses shims. I imagine that is probably the way to go, but im checking out my options as we speak.

9 minutes ago, oSkylines said:

I see tomei has a kit that you can basically falsify the A-OKAY  report back to the ECU, and uses shims. I imagine that is probably the way to go, but im checking out my options as we speak.

Nah. Complete removal and destruction. The use of lockout collars and lockout bars, retaining the crappy old tie rods and tie rod ends is....the nasty 90s style way of doing things. These days you can get brackets that are used to mount to control arms that replicate the setup of non-HICAS rear ends. These are literally called HICAS delete kits, as opposed to the HICAS lockout kits of yestercentury. You can knock the ball joints out of the steering arm on the knuckles and replace with bushes or bearings that get rid of the slop.

What I did instead was replace the entire rear subframe with a non-HICAS one, pulled out the solenoid valves, plumbing and changed the PS pump (this is an R32 with an R34 motor in it, so was hydraulic HICAS, which is the worst of them all, and the R34 motor brought along its PS pump for a no effort contribution to the HICAS eradication programme). But I suspect that that will be a bit harder on a GTR. I could use an A31 Cefiro subframe which I found lying around.

And you don't need to worry about any happiness or otherwise of the HICAS CU and anything it might say to the ECU. For one thing, you have a Haltech and it simply won't care under any circumstances. But I don't think even the stock ECU would give 2 shits. It certainly doesn't in the R32. Remember, these are vintage cars. Not the heavily integrated shitboxen of the last 20 years.

  • Like 1
3 minutes ago, GTSBoy said:

Nah. Complete removal and destruction. The use of lockout collars and lockout bars, retaining the crappy old tie rods and tie rod ends is....the nasty 90s style way of doing things. These days you can get brackets that are used to mount to control arms that replicate the setup of non-HICAS rear ends. These are literally called HICAS delete kits, as opposed to the HICAS lockout kits of yestercentury. You can knock the ball joints out of the steering arm on the knuckles and replace with bushes or bearings that get rid of the slop.

What I did instead was replace the entire rear subframe with a non-HICAS one, pulled out the solenoid valves, plumbing and changed the PS pump (this is an R32 with an R34 motor in it, so was hydraulic HICAS, which is the worst of them all, and the R34 motor brought along its PS pump for a no effort contribution to the HICAS eradication programme). But I suspect that that will be a bit harder on a GTR. I could use an A31 Cefiro subframe which I found lying around.

And you don't need to worry about any happiness or otherwise of the HICAS CU and anything it might say to the ECU. For one thing, you have a Haltech and it simply won't care under any circumstances. But I don't think even the stock ECU would give 2 shits. It certainly doesn't in the R32. Remember, these are vintage cars. Not the heavily integrated shitboxen of the last 20 years.

well, i can say an entire subframe swap is not likely something ill get that far into, but I am watching a video right now about the delete kits that essentially just replace the control arms and stuff to lock it into place. So, if the haltech isnt gunna care about the HICAS system if i lock it out, I'll likely just do that then. I did read on one of the HICAS threads that you actually were on ( i think from like 2021) something about pumps potentially overheating or something , so ill have to re-find exactually what was being talked about there for context, but i think it was something along the lines of if you were just blocking things off, whereas if you just delete the whole rear hicas system , there shouldnt BE any pumps to overheat, so unless the concern would be with some other pump somewhere its probably a nonissue. That being said, cant hurt to re-read so i can make sure i dont bugger something up unintentionally out of ignorance. 

So the potential issue with the pump is that it has 2 stages, the first is for power steer and the second for hicas. If you just block off the second stage outlet it will kill the pump.  

You need to either:

-Open the pump and remove the rear pump vanes, then block the outlet, or

-Reroute the power steering lines so the second stage feeds the PS cooler (then back to the reservoir) and the first stage just does the steering rack.

-replace the factory pump with a single stage pump, keep in mind the number of ribs in the PS belt are different between R32 (4 rib) and R33 (3 rib)

-loop the HCAS feed back to the HICAS return near the diff, although this keeps a lot of unnecessary weight and leak opportunities

  • Like 1
10 minutes ago, oSkylines said:

something about pumps potentially overheating

3 minutes ago, Duncan said:

So the potential issue with the pump is that it has 2 stages,

This is all only true for R32, which had hydraulic actuation of the rear rack. The R33 onwards cars had electric rear racks, which obviate all the hydraulic concerns.

Edited by GTSBoy
Just now, GTSBoy said:

This is all only true for R32, which had hydraulic actuation of the rear rack. The R33 onwards cars had electric rear racks, which obviate all the hydraulic concerns.

if this is accurate with the R33 not having  this issue, that is quite good news.

49 minutes ago, oSkylines said:

if this is accurate with the R33 not having  this issue, that is quite good news.

If by "this" you mean only the hydraulic associated issues with deleting HICAS, and not the fact that electric HICAS is still equally capable of trying to kill you as hydraulic HICAS is, then yes. It is easier to get rid of R33 HICAS than it is on R32.

  • Like 1
10 minutes ago, GTSBoy said:

If by "this" you mean only the hydraulic associated issues with deleting HICAS, and not the fact that electric HICAS is still equally capable of trying to kill you as hydraulic HICAS is, then yes. It is easier to get rid of R33 HICAS than it is on R32.

i was just referring to not having to worry about the pumps on the 33 overheating, since its not the hydraulic system and doesnt have the extra fins and pumps and shit running to the back. 

 

As for the HICAS being a death trap at one point or another, You have me sold on that. Well you, mixed with the fact that my car tried to do the cupid shuffle on its own , nearly taking out a motorcycle driver ( if it had been moving to the left instead of the right on its random swerve)

18 minutes ago, oSkylines said:

i was just referring to not having to worry about the pumps on the 33 overheating, since its not the hydraulic system and doesnt have the extra fins and pumps and shit running to the back. 

 

As for the HICAS being a death trap at one point or another, You have me sold on that. Well you, mixed with the fact that my car tried to do the cupid shuffle on its own , nearly taking out a motorcycle driver ( if it had been moving to the left instead of the right on its random swerve)

Almost every I know with an R32 GTR has some story about the HICAS trying to steer them in an unintended direction. The R33s seem more reliable in that regard. I'm pretty sure my HICAS is not locked out and I can't even really tell if it's working or not.

8 minutes ago, joshuaho96 said:

Almost every I know with an R32 GTR has some story about the HICAS trying to steer them in an unintended direction. The R33s seem more reliable in that regard. I'm pretty sure my HICAS is not locked out and I can't even really tell if it's working or not.

well, if the R33 is more reliable in this regard, maybe i am just wildly unlucky. Either way , If im planning on making changes in the near future by way of increasing power , after this week, I want mine off and in a dumpster somewhere. The injectors are the last part im waiting for to upgrade my fuel system at the moment, and then I have to run a few logs for my tune, one of which being a WOT run. Last few times i did my WOTs i was somewhere up in the 130ish mph area... I dont even want to know what would would've happened if my HICAS decided to go rogue on me when I'm doing my WOTs for tuning. 

Edited by oSkylines
4 hours ago, oSkylines said:

well, if the R33 is more reliable in this regard, maybe i am just wildly unlucky. Either way , If im planning on making changes in the near future by way of increasing power , after this week, I want mine off and in a dumpster somewhere. The injectors are the last part im waiting for to upgrade my fuel system at the moment, and then I have to run a few logs for my tune, one of which being a WOT run. Last few times i did my WOTs i was somewhere up in the 130ish mph area... I dont even want to know what would would've happened if my HICAS decided to go rogue on me when I'm doing my WOTs for tuning. 

I have had two separate R32 owners tell me about 2-3 incidents where they were either in a turn and the HICAS was trying to make the car go straight or they were going straight and the rear end was crabbing out to try and make the car turn. Neither could get it to reproduce again afterwards. It absolutely destroys confidence in a car when the system can randomly misbehave like that. My R33 doesn't do that but I have heard of bad yaw sensors causing behavior like the rear end crabbing out under braking or excessive vibration/exhaust noise doing something similar as well. The R32 doesn't have any form of feedback control and as far as I can tell the HICAS is really far more aggressive compared to the R33.

HICAS in the R32 and R33 both belong in the bin.

First real handling mod I did was delete HICAS, followed by a proper mechanical LSD (albeit I have a GTS-t shit box).

R34 HICAS is barely ok, if I had a R34 I would delete it as well.

2 hours ago, joshuaho96 said:

I have heard of bad yaw sensors causing behavior like the rear end crabbing out

No yaw sensors in HICAS. It's usually the steering angle sensor, but also can originate in the HICAS CU. The Oz delivered R32 GTRs had a factory recall to repair the CUs which sometime had a loose screw running around inside shorting shit out, and electrolytic capacitors all eventually reach EOL, etc etc.

 

2 hours ago, joshuaho96 said:

The R32 doesn't have any form of feedback control

No HICAS has any form of closed loop. It just sends out the "wiggle the rear end signal" when it thinks you'd like it to turn in. If that happens to be when you are sawing away at the wheel trying to fight understeer midcorner on a wet track, then so be it!

37 minutes ago, niZmO_Man said:

My HICAS actively tries to kill me (random kicks in the steering, rear end is looser than a drunk 18 year old at Ivy).

That 1986 shit should go straight in the bin.

Please delete it.

  • Like 1
11 hours ago, GTSBoy said:

No yaw sensors in HICAS. It's usually the steering angle sensor, but also can originate in the HICAS CU. The Oz delivered R32 GTRs had a factory recall to repair the CUs which sometime had a loose screw running around inside shorting shit out, and electrolytic capacitors all eventually reach EOL, etc etc.

 

No HICAS has any form of closed loop. It just sends out the "wiggle the rear end signal" when it thinks you'd like it to turn in. If that happens to be when you are sawing away at the wheel trying to fight understeer midcorner on a wet track, then so be it!

image.thumb.jpeg.89539a505f7ffa85e5a8fb421945bbed.jpeg

As far as I know there's actually a yaw sensor in the back of the R33 and R34 GTR which is used for HICAS. It vaguely helps maybe. In practice the R33 and R34 group N cars AFAIK kept the yaw sensor but deleted the HICAS and fed the signal into the ATTESA/ABS controller instead to control the A-LSD.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Maf is a question mark but TPS  I have set at 0.47, the fact that I’m getting proper voltage range out of it with the key on leads me to believe it’s functioning properly. I’m getting proper voltages on basically everything. I still need to look up voltage ranges for z32 maf and test that 
    • Honestly no not at all, but it’s a very basic tune, it’s stock injectors q45 tps and z32 maf. Other than that it’s a completely stock base map. The file is from nistune and from my understanding if it was tune related I would be able to unplug maf and tps and it would still start even if it was a really shitty start. I have tried starting it with coolant temp, maf, and tps unplugged none of those 3 togethor or individually changes anything 
    • 🏆 Skyline Supremacy Meets Mount Panorama Magic 🏆 Join SAU NSW as we take the long way to Bathurst, the home of GTR greatness. Saturday 30th August 2025 7:00AM Meeting Hanna Park North Richmond 7:30AM Departure Cruise Via Bells of Line Road 9:00AM Arrival to Stop 1: Golden Poplars Meadow Flat 9:45AM Arrival to Final Destination: Mount Panorama Motor Racing Circuit Meet Location: Hanna Park North Richmond Stop 1: Golden Poplars Meadow Flat Final Destination: Mount Panorama Motor Racing Circuit   *Disclaimer* There will be a lead and follow car so no one should get lost. If you would like to attend or bring others along please put your name down and a +1 as numbers will be needed prior! This is NOT a race and we will all be adhering to all road rules. If this is what you want please come to one of our many track days. This is an official SAU:NSW event and will be run under a CAMS permit. One of the things that really sets our club apart is our commitment to being true enthusiasts. When on normal roads we strive to maintain good relations with the authorities as well as the public in general. When attending one of Skylines Australia NSW events please try to: • Be aware of surrounding environment and act accordingly. • Drive courteously on the state’s roads as a true enthusiast should. • Understand how important it is to maintain the good name of SAU NSW and thus, treat others accordingly. • Any misbehavior will not be tolerated and you will be asked to leave.
    • What does it look like with highway driving? And yes, I had a similar thought as Duncan. It looks quite similar in my Stagea and I have made myself accept it as normal. Might have to look into it some day   Highway gets as low as 10l/100km on my end so I'm not as worried about it being a mechanical issue. More likely just the tune on the haltech.
    • While I was waiting for the new parts to come in for the charge pipe and radiator I decided to do some turbo modification. The drive pressure (exhaust backpressure) was a lot higher that I thought it should be. For 32lbs of boost drive was 55lbs. The turbine housing is a 1.10AR and my turbo builder has suggested to go to a 1.25AR. To test if a larger AR would do anything to reduce drive pressure AND not spend any money I decided to hog out the divider in my current housing. I removed it from the inlet and the whole way through the housing.  After reassembly and testing it doesn't look like this modification did anything for reducing drive pressure or requiring more fuel (making more power). Oh well, it was worth a shot. We'll get some data at the track if it makes it past the 60ft. I also machined a $7 shift knob off Amazon to fit my Stillway shifter since I didn't like the Stillway shift knob. Next on the list was the radiator replacement and fabrication of a new intercooler tube that had no silicon coupler. No pictures of this - I was short on time each night after work to get this done and didn't stop to take pictures.  Next was to get the clutch disks out and replaced. Previously when installing the dogbox I had ordered a set of the same sintered iron disks I had been running because I switched to the 26-spline input shaft. I thought it was odd that they didn't have any markings or brand name on them like all my old disks had but installed them anyway. At the track I could not get the clutch to lock up using my normal strategies. After two track nights I reached out to the clutch manufacturer and ask their thoughts. They said they had to switch the material out because they were having trouble getting the original material and that this new material would not take to being slipped very well.  So out with the first set of 26-spline disks and in with the correct material 26-spline disks. While I had the trans out I added an inspection/service hole. I've wanted one of these for a while. Now I can have a look at things and change the front cover shimming when needed (clutch wear). I hustled and got the clutch change done in a few hours on a Saturday. Hopped in the car and drove home. On the way home I did a 1-3 pull. When shifting from 2nd to 3rd the core plug in the back of the cylinder head popped out and dumped all the coolant. Thankfully I was only 30 seconds from home and coasted it there. Datalog showed nothing unusual and 2.5psi of coolant pressure. That plug has been in there since 1992 but I guess it worked its way out. Pulled the trans AGAIN and replaced the plug, JB welded it in, and made a brace. Also deleted the head drain I had added in during the bearing issue fiasco.  I am currently changing my boost control plumbing to make it cleaner. After that is done I'll make another attempt at getting past the 60.
×
×
  • Create New...