R32 Gtr G Sensor Fix

[datsun_1600]

Jeff,

I followed your tutorial and my voltages are way off even after adjustment. I got 2.45, 2.6, and a pot that cant go past 1.9. The electronics store I have on island (Okinawa, JP) doesn't have the pots so I'm kinda stuck. Here's where my real question comes in....I didn't get the 4WD light on until I was removing tint from my back window (also turning my car off and on occasionally for some background music). Is it possible that I just smashed on a wire somewhere around the back seats and broke it that way? I am getting error code 13 which to me sounds like it has a connection to the sensor but still it hangs in the back of my mind about looking in the wrong place. I'm interested in buying a completely electronic system like the one you're making and there is another one built and currently being tested over Here

Hey - I guess it's possible that a wire got broken - but with the voltages you have I would expect and error code 13... Sounds to me like the sensor is buggered - but I could be wrong....

Jeff

[datsun_1600]

Back from wedding holiday etc - i'll finish off that writeup on fixing that sensor this weekend....

[Bozz]

I've also modified the standard G sensor to fix the shit handling of stock R32 GTRs as first described by our mate Mr Edgar in this excellent article:

http://autospeed.com.au/cms/title_Godzilla-Tamed-/A_107753/article.html

I pulled apart the G sensor, drew a circuit diagram and went from there.

By increasing the bias to the front, my comments are the same as Julian's - the car is now a frighteningly quick, this mod alone is better than every other modification I've done to the car combined!

At Sandown, go slow into any corner and put the foot down hard as you begin any turn - the car now stays glued to the track, no power oversteer at all. Too much front bias and it understeers a little under power, set it to your cars configuration and its just magic, the car is so much faster through and out of corners.... My top speed is about 20-25km/h faster down both straights after this mod

I'll post what to do and photos soon.... I need to do a permanent install in my car, currently i've just got a wire coming out under the center console, soldered to a potentiometer.... looks nasty but works awesome as I was developing it. The mod is extremely simple - drill a hole in the top of the G sensor housing to run a two wires through and connect the two wires to a pot to adjust front bias.

[SiR_RB]

adjusting front bias, does that just involve in increasing/decreasing the voltages to a specific preset?

am very keen to try this !

[Bozz]

Yup, all it does is adjusts the negative feedback to the lateral G-sensor.

More negative feedback = less voltage swing from 2.5v at the output of the G-sensor = more 4WD goodness

[SiR_RB]

Sweet, can't wait for the step by step instructions on how to do it yehh buddyyy

[Samwest.M]

I borrowed the picture and translated this to Swedish for the swedish Skylines. This worked like a treat! my problem was that one of the transistors had a small leak, and the problem was the leak as it interuppted the the other pins.

[mjtown]

Jeff, you're a genius. Thankyou for your time today and thankyou for fixing my g-sensor mate. It's awesome how much the handling (particularly accelleration) is affected by a working ATTESA system

[hks786]

Guys just been reading this can anyone assist with the following results:

Pin 6 gives max 0.25V

Pin 5 gives min 2.79V (goes to 5v)

Pin 2 gives min 3.17V (goes to 5v)

Just getting too little and too much volts.

Which components would need changing?

Any comments most welcome

[datsun_1600]

Guys just been reading this can anyone assist with the following results:

Pin 6 gives max 0.25V

Pin 5 gives min 2.79V (goes to 5v)

Pin 2 gives min 3.17V (goes to 5v)

Just getting too little and too much volts.

Which components would need changing?

Any comments most welcome

When you say "goes to 5v" what do you mean ?

Your pin 6 reading suggest either a bent pendulum or buggered hall effect sensors. It is possible to sort of make it work. But in my opinion I think it would be better to find a new / replacement one.

If you go all out and replace stuff it will work sum what, but the response from the 4WD system will be unpredictable. ie. Will come on too late, too early, too fast, or too slow...or the wrong amount of bias.

Jeff

[hks786]

Jeff

The voltages at pins 5 and 2 actually go up to 5V, the minimum possible by adjusting the pot are 2.79V and 3.17V respectively.

Yet at pin 6 the maximum possible is only 0.25V it goes all the way down to 0V when adjusting the pot for this one.

Cant fork out for a replacement one, would rather fix this if its possible...

[Sinista32]

@ hks786 - what model skyline ?

[hks786]

R32 GTR

[GTRPSI]

Jeff

The voltages at pins 5 and 2 actually go up to 5V, the minimum possible by adjusting the pot are 2.79V and 3.17V respectively.

Yet at pin 6 the maximum possible is only 0.25V it goes all the way down to 0V when adjusting the pot for this one.

Cant fork out for a replacement one, would rather fix this if its possible...

Have a close look at the caps, even if one is just slightly bulging on its lid is a hint that its on its last legs, any leakage and its 100% gone.

Last resort if your stuck and unsure is unsolder a leg off one cap and check the voltages, if you lost voltage on one that was working before solder it back on till you find the cap that relates to that voltage your missing, when you have worked out which cap it is try other new cap, they are cheap as chips.

[datsun_1600]

Jeff

The voltages at pins 5 and 2 actually go up to 5V, the minimum possible by adjusting the pot are 2.79V and 3.17V respectively.

Yet at pin 6 the maximum possible is only 0.25V it goes all the way down to 0V when adjusting the pot for this one.

Cant fork out for a replacement one, would rather fix this if its possible...

Sorry missed this. Based off these voltages i'm guessing the G sensor is too far gone to fix. As mentioned above, try the caps as they only cost almost nothing, but I'm guessing a new G sensor is in order....

[TerryO]

I've got a R32 G senor i'm planning to use in a 2wd race car, jsut to check lateral G and to help detemrine the effect of various suspension/tyre changes.

can anyone explain how a sensor gets to display 'red" in the window?

does anyone have a complete pin-out diagram for this sensor. i cant find what i want with over an hour of google searching

thanks

[Duncan]

can anyone explain how a sensor gets to display 'red" in the window?

well I know rolling the car 7 times into a gully will do it.

the indicator is not connected to the sensor in any way (well except the glue that holds it on). It just breaks and goes red when it has a large impact because it is likely the g sensor will also have been damaged.

[Duncan]

BTW there are probably cheaper ways to get a g sensor, most logging systems/dashes have them already integrated. If you use the standard one you will need to connect to it and calibrate it. Also, RWD or not, you probably want both lateral and longitudinal sensors

[hotz]

Hi Jeff,

Great explanations!

We've got an R32 GTR in Adelaide and we believe we have the same symptoms, ABS & AWD lights on w/ codes 11 & 13.

We've tried to adjust the pots but no success. All three go up to about 1.2v and then drop to zero.

Would you please help us out?

Thanks mate.

[datsun_1600]

Hey,

Yeah sounds like the G-Sensor is the problem. Unfortunately it sounds like your sensor might be beyond repair :-( I have tried to repair sensors like yours in the past, but haven't had much luck. You can get them to stop throwing error codes on level ground, but the sensor characteristics are just awful. (ie Will engage front wheels at the slightest touch of the throttle, etc etc etc)

I would say a new sensor might be the best way to go.

Sorry I can't help more here. Wish I finished the little PCB replacement for the R32 I was working on. Twin babies seem to have gotten in the way of car projects....

Jeff