R32 Gtr Awd Kicking In When Not Needed

[Willis]

Hi all, i just purchased my first R32 GTR on the weekend and upon driving it home have discovered this interesting issue.

I have searched already to try and find a problem the same as mine with no luck..

So i thought i'd create this thread and get all your opinions!

The situation: AWD works correctly (as far as i can tell) when there is legitament slip. The AWD light comes on upon start up like normal, then dissapears and does not return. NO AWD LIGHT ON WHEN FAULT IS OCCURING. My HICAS light is on however the car has an aftermarket wheel and i believe this is unrelated to the AWD issue?

I noticed the issue on the highway, at a constant speed with the motor under load (100kph / 110kph) everynow and again the AWD kicks in with the "torque gauge" registering a constant reading of 10, there is also a distinct noise associated with the AWD's operation (i believe this is due to a "slipping of the clutch / driveline to the front wheels") the problem however is that the AWD won't disengage automatically .. the throttle needs to be backed off for it to return to 100% RWD. This occured 10+ times over a 300km drive .. it seem's "bumps" caus this issue to occur more frequently.

Has anyone encountered this sort of an issue before? or does anyone have any idea's?

Any help or advice would be greatly appreciated.

Additional info: The car is quite standard, cat back exhaust, "chipped" ECU running 13.5PSI making 239RWKW's - was tuned at RACEPACE 6 months ago. R34 GTR injectors, front mount oil cooler / aircon condensor. Car also has standard wheels, with 225/50 all round, the diff is quite noisy also.. .. not sure if any of this info is handy but i thought id mention it just in case.

Cheers for any advice,

Willis.

[SiR_RB]

open the interior panel on the right hand side of the boot and make sure fluid is topped up.

the transfer case might need to be bled properly aswell..

[CeJay]

Have you checked your attessa ecu for any error codes?

[Willis]

Thanks for the reply's. I havnt checked the attessa ecu yet, will do that though and post my findings here.

SiR RB the fluid in the attessa bottle in the boot is below the "low" line, but only just (less then a cm below the line)

How sensative is this level? There is pleanty of fluid in the bottle still.. could this be causing the problem?

[SiR_RB]

top it up to the HIGH mark and go from there

[Willis]

Will do. What should i top it up with??

I read about using Castrol Transmax Z? Can this be mixed with whatever is already in there? I have no idea what fluid is currently in there.

What would you suggest to top it up with?

Edited July 19, 2010 by Willis

[doo doo]

power steering fluid.

[Willis]

any type? or the Nissan specific fluid?

[doo doo]

Nissan special power steering fluid is what the manual says. There's a fluids link at the top of this section that has more info (page 2 has a post near the bottom discussing the different viscosity required for attessa)

[Moodles2]

Check your tyres, do you have the exact same profile all around (ie 225/50/16 etc), and is the tyre brand and model the same on every corner. Also check you have the same tyre pressure on every corner.

[doo doo]

Are you in Brisbane? Would you like a hand checking it out?

[Willis]

doo doo i am currently in Wagga Wagga for work, and will be down here till christmas i'm afraid, but thanks a bunch for the offer.

i found mechanic who is a GTR enthusaist and owns a killer r32 GTR, and i am taking up my issue's with him! Hopefully it won't be too tricky to work out what's wrong.

Tyre's are all identical, and they are wearing evenly. Tyre pressure's.. not 100% sure, as we havnt checked them yet, will try that also. I'll have a good look over the car again this weekend and see if i can't get all the things you have suggested done.

Thanks again for your inputs.

Cheers!

[R.3.2.G.T.R]

umm i have this happening on my car and had always assumed it was normal, fluid topped up, might have a go at bleeding it again

[Willis]

Well i'm still learning but i am inclined to believe that this is NOT normal operation, as it will wear out the front driveline components as it's "slipping" 10% traction to the front.. and the noise that is associated with it doesn't sound healthy.

I will obviously post up here when it work out what it is!

Edited July 22, 2010 by Willis

[CeJay]

One tip a shop told me is check the wiring underneath the centre console where the G-Sensor is. Perhaps an aftermarket unit controller was used in japan, or something is loose. Not sure if it is related to your problem though, just thought I'd mention it.

[gwin]

Faulty G sensor.

[R.3.2.G.T.R]

Faulty G sensor.

I once read on here it may not be getting the correct voltage

indicator on g-sensor is fine

[gwin]

Yea, the g sensor is quite complex, it takes into account steering wheel angle, G-sensor, wheel speed sensors etc..

If your G sensor is fine, then it's the painful process of elimination

Best to bring it to a shop to plug in diagnosis? I recall it will pick up faulty sensors

[doo doo]

the gauge going up to 10 in your driving scenario is not normal, some engagement of the system is though. I would also be checking the G sensor for being loose or previously modified in anyway. The AWD doesn't 'slip' as the wheels are going the same speed, only time there's a difference in speed is when you have wheelspin, so you don't need to worry that it's wearing out the system. I would imagine that any noise associated with it's operation is old bearings taking the load of the hydraulic action against the transfer case clutch pack when system engages, or possibly the hydraulic pump itself (which shouldn't be that loud anyway)

[Willis]

Well i'm glad that it isnt wearing out the system. Cheers for clearing that one up for me doo doo.

Yes i think i'll get my new mechanic to take a look.. hopefully we can find the problem!

Cheers again for all the input,

CeJay - i'll give that a go sometime for sure, cheers.