AWD not working

[Terrh]

There is no reason at all why I couldn't make replacement G-sensors with an arduino based device. What are these sensors worth used? The one I have here is effed for sure.

A friend of mine have dabbled in building a torque split controller but ADD kicked in and it never got finished.



It's just designed to control front wheel torque split (0-50% or roughly so, depends on how the tcase reacts to voltage) but it's untested so far.

It would only be one more step to add a G-sensor to this unit and have it completely replace the factory hardware. The way it sits right now it can bypass the factory AWD system entirely but you don't get a variable torque split, just whatever you set it to (adjustable on the fly).

[MarusGTR]

^ On ebay or most GTR forums around $300 CAD for a used one (R33, R34). New ones are $1000-1500...

I'm really surprised G sensors haven't been a debated issue... since they get so old and that the material is finite you'd think people would recognize some signs of lag in the G sensor output, just like I did. Sadly I don't remember how my AWD reacted when I first got her so I have nothing to compare to but I know for sure that right now it's not working properly (even if I'm not throwing a code).

If you could build a custom setup that implements itself in the OE setup i'd be interested...I was planning on getting my AWD circuitry custom engineered by a friend (my speciality is mechanics and fluids) for my future project. I had looked for individual G sensors with the same input voltage and pins and they came up at $30 a pop. If you need a proper working board, mine (my original one) is mint and gathering dust. I'd be glad to sell it to you if you can RnD a new system and sell it to me to a resonable price. Two of the sensors are A1 and the system would be easily reverse engineered. It's basically a combination of three redundancies for each direction, so you only need one circuit to duplicate the rest. I have two of three that are, in my opinion, like new.

But yeah... my custom engineered GTR project was a way future project since I don't have a job right now.

EDIT: LOL found a guy on nissansilvia.com that had been quoted one at nissan japan for $1600.

[Terrh]

Yeah, I'm pretty sure I can build something that I'd be willing to sell for under $500 that gives you a 0-50% torque split option, or flip a switch and you've got completely stock, replacing the G-sensor 100%.

I could probably build a unit that replaces the G-sensor entirely (but does nothing else) for around $150 (to cover time figuring out how to build it and ****, actual part costs would be less). My friend and I already reverse engineered the system to build what's shown above. Bypassing the AWD ECU is an option too for when those start to go bad, but again, you can only adjust torque split with ak nob at that point

[NeptuneGTR]

You guys should search up Grid T.S dancer snd Skylab tsc, the tsc alters the votage output increasing sensitivity and the grid overides the ets and allows constant spilt, but messes up the transfer case :S

Also I read that someone was working on creating a faster ets ecu, from 10Hz to 4Mhz maybe that would help get a better feel

or another thing you guys could do is turn the g sensor itself aroud 90 degrees for a better feel, fooling the ets from the outputs of the g sensor.

[MarusGTR]

Finally got a nice day and I realized I had a 5.5mm socket so I took the cap of my 2nd G sensor, tweaked the voltages back to 2.5 (they were at 2.6-2.7 mostly) and response has improved. I'm going 2/3+'s of the way on the gauge at WOT with my slowjoe stock engine (no launch).

[Terrh]

So I started working on this car finally to figure out what was wrong with the AWD. Only 4 months after I posted the thread to do 5 minutes of work. What can I say, I'm lazy.

Pulled the center console to have a look at the G-sensor and it was just GONE! Took the one out of my other GT-R and put it in and blam, AWD works perfectly. That was easy.

the 4WD light wasn't on in the dash because the same idiot that took the G-sensor also took the 4WD, HICAS and ABS bulbs out. I put them back in and now everything is peachy.

[MarusGTR]

What's your AWD's response on the torque gauge?

[Terrh]

I've only driven it about half a mile, but the gauge hit 30-40% when I was doing a donut in my back yard, moderate throttle in 1st gear.

[MarusGTR]

Okay something new popped up.

Now when the gauge goes full pin, I get a big vibration through the chassis, as if something is unbalanced. Anyone have a guess?

My guesses are:

-Propellor shaft got unbalanced/screwed up while driving in RWD for so long.
-Could be an issue with the ATTESA pump or the fluid, since it still has the original fluid and it was stagnant for 2000kms in RWD mode.
-The G sensor is slightly damaged... if the G sensor sends fluctuating voltage, it could make the AWD system clutch on/clutch off intermittently
-Front diff could need new fluid

I guess the front bearings could be an issue but I didn't feel anything in RWD mode and when braking hard with the AWD on.

Edit: I'm getting the vibration at random throttle position, but everytime I notice the torque gauge jolting. Sometimes I go WOT and the gauge doesn't budge; no vibration.

[MarusGTR]

[Terrh]

I'd check that your propshaft bolts are tight. Aside from that, I have no idea.

[Dragon Humper]

Bumping for some good reading here.



Jon.

[MarusGTR]

I guess the front bearings could be an issue but I didn't feel anything in RWD mode and when braking hard with the AWD on.

Edit: I'm getting the vibration at random throttle position, but everytime I notice the torque gauge jolting. Sometimes I go WOT and the gauge doesn't budge; no vibration.

God I was green back then. Hadn't even delved into the FSM yet.

As an update, turns out that second G-sensor was also bad. My current (and third) G sensor brought back things to normal, although the torque distribution is lazier than on my second. Again, I'm thinking its an age issue.

[rvander1992]

If you still have your old ones I'd suggest popping one open. While I was diagnosing I found a thread where the guy popped his open, resoldered all the connections then put it back in the car(still open) and re-alligned the potentiometers so that it was reading correctly again and that solved all his problems. it took him about half an hour as compared to a couple hundred fora used gsensor or 2 grand for new :P.

Also theres an aftermarket torque splitter kit that comes with an aftermarket gsensor that brings the r32 system up to something along the lines of r33. Costs about 300$ but gets you new parts and a torque splitter at the same time. I believe littledevilcrx told me about the aftermarket kit so I can't provide source for that, off into google to find the rebuild thread though. I'll be back later :P


edit: I'm back and that was easy to find.

http://www.skylinesaustralia.com/forums/topic/356654-r32-gtr-g-sensor-fix/

Skyline australia, put a new cap in cleaned up the board, remounted recalibrated restarted and problem gone

[Dragon Humper]

Nice...

I remember reading about the new version of the G-sensor with the controller somewhere too...seems like a no brainer if you want to get a splitter controller anyway.


Jon.