R32 Gtr G Sensor Fix

[datsun_1600]

Hi all, I think this is my first real post. Anyhoo, my G sensor started playing up and I had error code 13 with both the ABS and 4WD lights on my dash on. I decided to pull it apart and fix it rather than buy a new one. I'm a Digital Electronic Engineer but I think anybody could do this.

I started by pulling the G sensor out of the car, removing all the screws from under the bottom of the sensor and pulling the plugs off the top of the sensor to make it easier to work on.

After I pulled the sensor apart the first thing I noted was that an electrolytic capacitor had been leaking which had caused some corrosion on the PCB. I replaced the leaking caps, cleaned everything with PCB cleaner and remounted the sensor back in the car _without_ the metal housing on.

After stating the car (in neutral on a level surface) I noted the three output voltages (see attached pic). One of mine was 2.53v the others were in the 2.20~2.31 volt range. I then adjusted the calibration pots (again see pic) so that all the output voltages were exactly 2.50volts (netural for the ATTESA computer). I shut the car down, restarted and abracadabra no more ABS and 4WD lights.

FYI if you blow something up or damage anything following this it's not my fault!!

Apologies if this is already up on the forum somewhere (I couldn't find it)

Link to pic - https://www.facebook.com/photo.php?pid=6875962&l=54a7f3bd68&id=616436020

Jeff T

[GTRsean]

Good job!! that should point a few guys in the right direction as I usually just tell em to check the g sensor for the indicator bar to see if it's stuffed.

Had the same issue with a guys computer in his honda lol, leaking caps caused car not to start, replaced them and good as new.

[Victory]

Considering that Nissan want over $2,000 for a new G sensor this DIY could save people a lot of money.

Nice work...

[Gazelle D]

mate thats awesome, i was just about to buy another G sensor !

thank you. davo

[datsun_1600]

Let me know if the fix works for you too :-) I did this on an R32 GTR VSpec not sure if all the other GTR's (R33's and R34's) are the same or not...

Jeff T

Edited March 9, 2011 by datsun_1600

[YunisA]

I am having the same problem, error code 13 fore and aft g sensor.

I will certainly give this a go. The funny thing is the car was kept off road in the winter and when I first started it up 4wd worked fine, then after a few hours went back to 2wd mode with the abs light kicking in. I did notice that the voltage was a little lower as per the first post.

I hope this works. Many thanks.

[datsun_1600]

That's really interesting - my car was off the road for the winter too and had the same thing after a day or two of driving the error cropped up.

[YunisA]

Yeah that was pretty much the case.. I pm'd you on FB last week, still got to go through and try this with adjusting the voltage. Need to find a flat place as where I am there are lots of hills.

[YunisA]

I tried this today, but one of the pots could not be adjusted for 2.5v the highest it would go was 2.14v while the others were 2.5v and 2.54v. Any ideas why I cannot exceed the voltage past 2.14v?

[zr200]

excellent post.

my car is doing the exact same thing, will have to get in and have a go at this.

where do you check the voltages at? sensor plugs?

cheers

[R.3.2.G.T.R]

did this today.. my pin 2 (2.63v) pin 5 (2.67v) pin 6 (2.60v)

i couldnt adjust these any lower as it switches to ~1.64v and abs light comes on

am i missing something?

[datsun_1600]

did this today.. my pin 2 (2.63v) pin 5 (2.67v) pin 6 (2.60v)

i couldnt adjust these any lower as it switches to ~1.64v and abs light comes on

am i missing something?

If it's jumping from 2.67ish to 1.64 then you might just be turning the pots the wrong way. They can be turned 360deg and the bottom say 60 deg is just open so the voltage will jump. When I get my butt into gear I'm going to post a replacement pot that can be loaded that will allow a larger range so units that are a bit out of whack can be fixed still.... Just got home from a couple of weeks on the road, so hopefully in the next few days i'll pull my unit out and work out a replacement part that can be loaded. (FYI only a few bucks each (or maybe cents) for replacement pots)

Jeff

[YunisA]

Same as mine, 2 pots are 2.50, but the other does not go above 1.14v so I guess thats an issue with the pot, Hopefully once that is replaced it all starts to work again.

[kingluke13]

Hi mate my GTR has done the same thing. Have you had a chance to look at different pots that will allow greater range adjustment?

[datsun_1600]

Hey sorry for the delay. Some of the equipment I design is used in the shuttle launches and I was invited by NASA to go to the last one. I get back to Aus on the 6th of Sept so i'll have a crack at it then. I haven't forgotten!!!! I'm also in the process of building a replacement with today's modern IC's, but lol i get busy with work so i have no idea when that will be done. Funny that about $20 bucks worth of today's IC's can replace a $$$$$$$ unit. Jeff

[kingluke13]

Not wrong I cant believe the price they charge for the new one when you consider whats in them. My mechanic who specialises in GTR's spoke to the local dealer and said he was lookign for one and when he was told the price he laughed and said you mustnt sell many of them and the guy said no they dont fail that often, at which point my mechanic let fly with a few choice words and said they fail all the time its just that no one is prepared to pay for a new one.

[datsun_1600]

Yeah totally. Hopefully when I get a spare moment i'll finish off my idea for a new module and make the project open source etc so everyone can have it. Using a Bosch Sensortec BMA180 G sensor, Altera Cycline II FPGA, (not sure which DAC yet), JTAG etc etc etc. Another trade off is if you wanted you can play with the four wheel drive bias characteristics. I have the IC's but haven't done the PCB yet. lol i'll get to is sometime soon I hope... Hard to get motivated a bit coz I work with electronics all day at work, the last thing I want to do it work on electronic stuff after work too lol.

Jeff

[LightAssassin]

What would help motivate you? Couple drinks? a Pleasure woman? lol

Heck if donations would help you feel good I'm sure many around would donate just for the ability to get a design made.

Keep up the good work. Always good to see alternatives being built locally by skilled people. Always appreciate the efforts of those who have skills I don't =)

[Madaz]

^^Amen

[datsun_1600]

Bah just lost my last post...

Some testers in the Adelaide area (R32 GTR required) would be helpful. Better yet a track day or something (safer). I need to gather info from the factory system to calibrate mine, so I have to download info with a laptop after a few laps (hard, med and slow, and even grandma driving). I have all the components in now, just need to do the PCB when I get back home...

Jeff