Jump to content
SAU Community

Recommended Posts

Im curious to see of any one else has had or has this issue with their R32 GTR

When cruising my front tourqe guage bounces around the 6-10 mark and the vehicle has a pronounced surge as the front tourqe goes up and down, more so when its warm. The funny part is the problem is not there at first, then it comes in at cruise speeds only and on partial throttle, more driving and it becomes an evident surge on acceleration. Flick into 2wd and the problem is gone immediatly no matter what the conditions. So its 100% assosiated with the attessa contol not an engine misfire etc.

Under hard acceleration the transfer delivers front tourqe and works perfectly.

I have checked the diagnostics and aparrently everything is fine according to the control unit. So I pulled the mannual out and started working through the problem.

Firstly I have bleed the Attessa hydrolic control and used genuine matic D fluid.

I have changed the transfer case oil and again used genuine matic D fluid, also worth noting is the trasfer opperates normally when front tourqe is required under hard acceleration/ cornering.

I have checked all the speed sensors for continuity back to the control unit and sensor resistance. I have also checked the air gaps between the pick up rings and the sensor tips.

Ive checked the power and ground supplies to the control unit they are all fine.

I have checked the TPS and RPM inputs from the ECM to the contol unit, again they are all fine.

Now this brings me to 2 items. The G sensor OR the control unit.

My thoughts on the G sensor, is it possible for the G sensor to be getting "stuck" in the acceleratinn or deceleration position and be feeding the control unit false information??

A simple check with the mulitmeter will confirm or dispel this and ill be doing it tommorrow.

I know at rest I should have a 2.5 volt referance from the sensor. accelleration it goes up, decel it goes down. I may have that arse about but its late!

So this quick check should rule out the G sensor and point my last resort towards the conrtol unit itself.

Is there anything im missing in this diagnosis that people have come accross before??

And finally split conrollers, most of the ones I have seen simply bend the G sensor referances. Are there any different versions that actually control the pump directly??

If it turns out to be a control unit I think something along these lines would work out to be a more cost effective solution to replacing the control unit.

Also on this particular vehicle all the wheel dimensions are the same 17 by 10's with 40 series rubber.

Brad

Edited by Risking
Link to comment
https://www.sau.com.au/forums/topic/131208-r32-attessa/
Share on other sites

does it sit at its minimum value when cruising, and flicks under acceleration?

what size are you tyres / rims ? I had that issue when I had to run around for a week with a space saver on. different rolling radius...

Though from your diagnosis, I guess you know that your tyres are all equal. But the next step after rolling radius would have to be abs sensors (the reason rolling radius matters).

rolling radius

rolling radius

I just wanna say rolling radius.. rolling radius rolls off the tongue. radius. rolling radius.

Er.. um... The attesa cpu is very dererministic on how it treats the voltage values. I'm (eventually) going to wire up a semi - fixed option (much lower teck than duncans controller)... eventually... I still have to sand an ugly fibergalss patch... still....

The surging like you describe shouldn't be because of the G sensors, it wouldn't manifest itself that way. Rolling radius (ha - said it again) and abs sensors.

And then hopefully someone who has actually tinkered with it (instead of reading alot) might have an answer.

I'd get to it quick though. How much are new clutch packs? On the plus, when its wet, it absolutley rocks...

Link to comment
https://www.sau.com.au/forums/topic/131208-r32-attessa/#findComment-2427814
Share on other sites

Are the tyres all the same size, in terms of wear. If not, then you have a different rolling radius - you're right ebola, it's really smooth off the tongue! - front and rear.

If you have replaced only one pair, try swapping them to the other end of the car.

One other possibility is a localised wear pattern on the TPS which may send a variable voltage signal back to the ECU.

Link to comment
https://www.sau.com.au/forums/topic/131208-r32-attessa/#findComment-2428429
Share on other sites

Rolling diameters are the same and I have tried 3 different sets of wheels all with matching tires.

Brand new rubber all round so it NOT tires.

Read the post I have checked the ABS sensors and air gaps. Im a certified nissan mastertech so I know what im doing when it comes to diagnosis, ABS sensors were the first thing looked at.

TPS voltages are fine right from closed throttle to full throttle. I have confirmed this via the power FC and also substituting a OEM ECM and using genuine nissan consult II.

I have narrowed the problem down to the G sensor, After driving it hard tonight I have noted that once the G sensor is loaded upon turn in the attessa opperates normally and the guage goes back to 0 untill the vehicle trajectory is straight again.

Turning the sensor 90 degrees it opperates fine in a straight line but surges when cornering.

Ill substitute a sensor out of another one of the GTR's tommorrow and hopefully it will rectify the problem.

Link to comment
https://www.sau.com.au/forums/topic/131208-r32-attessa/#findComment-2429942
Share on other sites

>aparrently everything is fine according to the control unit

what does this mean? no flashes? could the control unit be stuffed?

have you tested the resistance and voltage across the control unit/harness/g sensors? could it be that somewhere something is firing the g-sensor with greater voltage?

hope you sort it out mate - my attesa is also stuffed so i do understand :(

btw if you find a spare g sensor, let me know :D

Link to comment
https://www.sau.com.au/forums/topic/131208-r32-attessa/#findComment-2432311
Share on other sites

Hey - since I am guessing you will have the multimeter out, do you reckon you could get a mA reading from a G-sensor? I want to know what the minimum current required to consistently detect as an input is... and I don't want to fry the computer or cook the G-sensor voltage regulator

Eventually, to override the lateral sensor at 1-4V by hand... and perhaps to figure out how to put on a little preload. Short spurts only (or when its really wet... I live in Melbourne)

Thanks

Link to comment
https://www.sau.com.au/forums/topic/131208-r32-attessa/#findComment-2432472
Share on other sites

it is bieing NORMAL it sends torque to the front on aceleration not just wheel spin. this is it anticipating wheel slip.

bare in mind it takes a throttle position input as a main input. not just wheelspin as what most people think.

so driving along in say 3rd gear at around 3k. you floor it and evan befor it comes up on boost the front wheels are already being fed power.

if you think about it. the system has a degree of "lag" in its operation, in the form of relays,pumps,solinoids,actual moving of the fluid and also the slack in the transfercase and front drivelines.

this is the main diferance between 32's and 33/34gtr's the 32's dont run any "preload" on the transfer case clutch. where as the latter is preloaded. to give a quicker responce time.

i know its not very smart,but its job is to asume your about to get up it as soon as you put your foot down.

so dont stess its perfectly normal.

hope that helps ;)

ps... make sure the diagnostic plug is not pluged in. ie bleed mode.

to evan up the rolling diameter

i had a similar problem when i put new tyres on the front and had bald ones on the back. it was fixxed with new tyres on the back.

Link to comment
https://www.sau.com.au/forums/topic/131208-r32-attessa/#findComment-2432914
Share on other sites

I know what your saying and im very familair with how the attessa opperates and anticipates however this opperation is not normal. I own 2 R32 GTR's and only one of them has this issue.

Im aware under acceleration there is front tourqe being applied however when cruising there is not meant to be anything and what I am getting is fluctuating to the point of causeing a surge through the vehicle.

I had a line pressure guage on the pump today and its 100% getting front drive and fluctuations in the pressure while cruising. Not little fluctuations either, rather significant ones. When being driven hard the attessa pump works perfectly which tells me the actuator (pump) is okay its a control issue.

I have been over the loom front to back.

Ebola I can do that sometime tomorrow.

Link to comment
https://www.sau.com.au/forums/topic/131208-r32-attessa/#findComment-2433603
Share on other sites

  • 3 years later...

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

    • From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
    • Place the new daughterboard in the case and mount it using the 3 small black rivets provided, and reconnect the 3 factory ribbon cables to the new board Then, use the 3 piggyback cables from the daughterboard into the factory board on top (there are stand offs in the case to keep them apart. and remember to reconnect the antenna and rear cover fan wires. 1 screw to hold the motherboard in place. Before closing the case, make a hole in the sticker covering a hole in the case and run the cable for the android unit into the plug there. The video forgot this step, so did I, so will you probably. Then redo the 4 screws on back, 2 each top and bottom, 3 each side and put the 2 brackets back on.....all ready to go and not that tricky really.      
    • Onto the android unit. You need to remove the top screen because there is a daughterboard to put inside the case. Each side vent pops out from clips; start at the bottom and carefully remove upwards (use a trim remover tool to avoid breaking anything). Then the lower screen and controls come out, 4 screws, a couple of clips (including 3 flimsy ones at the top) and 3 plugs on the rear. Then the upper screen, 4 screws and a bunch of plugs and she is out. From there, remove the mounting brackets (2 screws each), 4 screws on the rear, 2 screws top and bottom and 3 screws holding in the small plates on each side. When you remove the back cover (tight fit), watch out for the power cable for the fan, I removed it so I could put the back aside. The mainboard is held in by 1 screw in the middle, 1 aerial at the top and 3 ribbon cables. If you've ever done any laptop stuff the ribbon cables are OK to work with, just pop up the retainer and they slide out. If you are not familiar just grab a 12 year old from an iphone factory, they will know how it works The case should now look like this:
    • Switching the console was tricky. First there were 6 screws to remove, and also the little adapter loom and its screws had to come out. Also don't forget to remove the 2 screws holding the central locking receiver. Then there are 4 clips on either side....these were very tight in this case and needed careful persuading with a long flat screw driver....some force required but not enough to break them...this was probably the fiddliest part of the whole job. In my case I needed both the wiring loom and the central locking receiver module to swap across to the new one. That was it for the console, so "assembly is the reverse of disassembly"
    • But first....while I was there, I also swapped across the centre console box for the other style where the AV inputs don't intrude into the (very limited !) space.  Part# was 96926-4GA0A, 284H3-4GA0B, 284H3-4GA0A. (I've already swapped the top 12v socket for a USB bulkhead in this pic, it fit the hole without modification:) Comparison of the 2: Basically to do the console you need to remove the DS and PS side console trim (they slide up and back, held in by clips only) Then remove the back half of the console top trim with the cupholders, pops up, all clips again but be careful at the front as it is pretty flimsy. Then slide the shifter boot down, remove the spring clip, loose it forever somewhere in the car the pull the shift knob off. Remove the tiny plastic piece on DS near "P" and use something thin and long (most screwdrivers won't fit) to push down the interlock and put the shifter down in D for space. There is one screw at the front, then the shifter surround and ashtray lift up. There are 3 or 4 plugs underneath and it is off. Next is the rear cover of the centre console; you need to open the console lid, pop off the trim covering the lid hinge and undo the 2rd screw from the driver's side (the rest all need to come out later so you can do them all now and remove the lid) Then the rear cover unclips (6 clips), start at the top with a trim tool pulling backwards. Once it is off there are 2 screws facing rearwards to remove (need a short phillips for these) and you are done with the rear of the console. There are 4 plugs at the A/V box to unclip Then there are 2 screws at the front of the console, and 2 clips (pull up and back) and the console will come out.
×
×
  • Create New...