Jump to content
SAU Community

Recommended Posts

Hey ppls,

hope someone can shed some light on the issue.

My 34 GTR with just the ignition on,the TPS gauge flickers from 0% to around 2%, but the power FC does not show ant voltage change (0.41v.

Is this normal???

and could it be why when i put my aircon on the LSD-4WD light come on.

do i need to reset the CPU and or do i need to calibrate my TPS,

by the way its a new TPS.

Thanks any advise would be great

mike

Link to comment
https://www.sau.com.au/forums/topic/349571-erratic-tps-34-gtr/
Share on other sites

  • Replies 42
  • Created
  • Last Reply

Top Posters In This Topic

0.41 sounds Ok to me

when you mash pedal with ignition on but car not running does TPS % change, the voltage on PFC should also follow

if TPS is toast or out of range the PFC will throw on the engine check light and its name will highlight under ETC, SENSOR SW CHECK with a black background

when does 4WD/A-LSD light come on? every time?, erracticaly? somtimes?

what mods done to the car? has it always been broken or only recently?

0.41 sounds Ok to me

when you mash pedal with ignition on but car not running does TPS % change, the voltage on PFC should also follow

if TPS is toast or out of range the PFC will throw on the engine check light and its name will highlight under ETC, SENSOR SW CHECK with a black background

when does 4WD/A-LSD light come on? every time?, erracticaly? somtimes?

what mods done to the car? has it always been broken or only recently?

Hi, yeah the Fc voltage follows the mfd signal,

the lights come on sometimes, but mainly when i turn the aircon on, after a few minutes or so.

The guy i bought the car off had the same problem so he replaced the TPS but has not fixed the problem.

The gtr has -5 turbos, 600cc injectors, fc boost controller, high flow fuel pump, few other mods but nothing more engine wise.

The TPS i assume has been stuffed for a while. Ive checked almost everything to do with this issue and think its possibly out of range and once the aircon comes on the the engine changes its base idle it sets it off.

i have not done a reset of the fc yet. i have to save the tune first and re-do the idle learn sequence.

Edited by trick

when the engine check light comes on, you need to check ETC, SENSOR SW CHECK and see which sensor highlights

my advice is leave the hand controller on this SENSOR SW CHECK screen all the time and when the engine light comes on look over and see whats highlighted

if the TPS is toast then it will highlight it

a busted TPS or one that goes out of range will kill A-LSD/4WD as the A-LSD/4WD computer in the boot needs constant stable TPS signal to detect how hard you flog the car

if TPS goes out of range the A-LSD/4WD computer will panic and go into failsafe mode, ie light comes on and it stays in RWD/Non vspec mode

when the engine check light comes on, you need to check ETC, SENSOR SW CHECK and see which sensor highlights

my advice is leave the hand controller on this SENSOR SW CHECK screen all the time and when the engine light comes on look over and see whats highlighted

if the TPS is toast then it will highlight it

a busted TPS or one that goes out of range will kill A-LSD/4WD as the A-LSD/4WD computer in the boot needs constant stable TPS signal to detect how hard you flog the car

if TPS goes out of range the A-LSD/4WD computer will panic and go into failsafe mode, ie light comes on and it stays in RWD/Non vspec mode

no worries ill do just that.

thanks heaps for your help

hopefully i can narrow it down

cheers

mike

i had the same problem about 2 years ago tried everything untill i finally gave up put the stock ecu back in and went to nissan to conect there scan tool and it said the tps was droping the voltage down to .41 at ilde, the minimum it should ever be was .45 at idle so i adjusted it buy loseing the 2 bolts that hold the tps and with a volt meter conected i turned the tps untill it read .45 and then tighen the bolts and recheck it jus to make sure as it was tightened it didnt change and never had a prob since.

interesting, ive been having the random rwd mode problem too.. ill also check my minimum tps voltage

thanks for the info

edit: i just checked it out now, it reads 0.28v on idle and 3.98v on full throttle (engine not running)

Edited by snozzle

also i forgot to mention make sure u test it by pushing the acclerator down and lift your foot of it fast so it springs back and then check it while u ease it off slowly while reading the volts before u drive it to make sure its right as u cant really check it while u driving

Ive got a power fc so its really easy to do it, no need for a multi meter etc. I re-adjusted the tps so that it now reads 0.47v with throttle off (it actually flickers back and forth from 0.46 to 0.47..) and 4.22v at full throttle.

I started the car up 5 times since then and the 4wd has worked every time! Thanks a million for the info, George, and also thanks to the topic starter. :P

Ive got a power fc so its really easy to do it, no need for a multi meter etc. I re-adjusted the tps so that it now reads 0.47v with throttle off (it actually flickers back and forth from 0.46 to 0.47..) and 4.22v at full throttle.

I started the car up 5 times since then and the 4wd has worked every time! Thanks a million for the info, George, and also thanks to the topic starter. :P

yeah have a fc too, adjusted to .45 but only goes to 4.00 full throttle?? should it be more at full throttle??

Thanks to all with the info, saved me time and monies

cheers

mike

  • 1 month later...

UPDATE:

played around with the tps, fluid level and still having the lights come on. thought i had it sussed but it still came on after a few days

my question is has anyone done the wire mod where you cut the pin #56 and join it to the pin #38 on a gtr?

i read the forums and seems everyone was having issues with a gtst with alsd.

is there a way to test if the alsd is getting the tps signal

thanks

mike

do not do that mod, that is for ECR33 only with active-lsd and a powerfc

this is because the powerfc in the ECR33 assumes the car doesn't have a-lsd as only a few models had it

the BNR/BCNR range of powerfc all assume this as far as i know and relay TPS correctly as its needed for the 4WD computer anyway

if it has no TPS signal A-LSD never passes diag when you start the car and it fails every time

so if yours is working and only randomly failing it could be a wheel sensor that is being whacko. does your ABS work OK? any ABS warnings as they use the same sensors

if it has no TPS signal A-LSD never passes diag when you start the car and it fails every time

so if yours is working and only randomly failing it could be a wheel sensor that is being whacko. does your ABS work OK? any ABS warnings as they use the same sensors

hey paul,

been playing around again with the tps setting it from 0.47v to 0.55 v just to see whats happening.

since playing around the lights come up about 30 seconds once ive started the car.

the fault codes are 72 (tps), but it also flashes 12? what is 12 code?

mike

no idea what code 12 is

if TPS isnt working your car would run like ass, peg its idle at 1500rpm instantly and A-LSD would always be on, among the engine check light too

so the TPS is OK

start your CAR when watching ETC, SENSOR SW CHECK and wait TPS when its working OK, and then watch TPS (and others) when A-LSD fails

does anything change or any sensors go black background

do any other errors come on other than A-LSD ?

but perhaps the TPS to the computer in the boot is being homo

only way would be to work out which wire is TPS relayed signal at the boot computer and check it there

very tedious and annoying

its very weird, sometimes it comes on straight away sometiimes it doesnt at all.

nothing seems to change on the power fc sensor check page, no extra dots.

once the lights come on it locks out some numbers on that page but nothing else.

i may need to test the attesa at the back and check the signal.

if its the abs wouldnt that come up as a fault code?

been testing the voltage at the fc. with just the ignition on the volts to the fc are 0.568, it matches the hand controller voltage. Also the output to the attessa reads the same.

Once ive started the car the voltage at the fc slowly drops to -0.36mv, as if its lost the signal but the hand controller still states it has 0.5v. now im confused. is this a correct reading for tps output or is this why my

fault light is coming on?, but the hand controller says its all good. ahhhhhhhhhhhhhh

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

    • You won't need to do that if your happy to learn to tune it yourself. You 100% do not need to do that. It is not part of the learning process. It's not like driving on track and 'finding the limit by stepping over the limit'. You should not ever accidently blow up an engine and you should have setup the ECU's engine protection to save you from yourself while you are learning anyway. Plenty of us have tuned their own cars, myself included. We still come here for advice/guidance/new ideas etc.  What have you been doing so far to learn how to tune?
    • Put the ECU's MAP line in your mouth. Blow as hard as you can. You should be able to see about 10 kPa, maybe 15 kPa positive pressure. Suck on it. You should be able to generate a decent vacuum to about the same level also. Note that this is only ~2 psi either way. If the MAP is reading -5 psi all the time, ignition on, engine running or not, driving around or not, then it is severely f**ked. Also, you SHOULD NOT BE DRIVING IT WITHOUT A LOAD REFERENCE. You will break the engine. Badly.
    • Could be correct. Meter might be that far out. Compare against a known 5 ohm 1% resistor.
    • @Murray_Calavera  If I were an expert I wouldn't be in here looking for assistance.  I am extremely computer literate, have above average understanding on how things should be working and how they should tie together.  If I need to go to a professional tuner so be it, but I'd much rather learn and do things myself even if it means looking for some guidance along the way and blowing up a few engines. @GTSBoy  I was hoping it would be as simple as a large vacuum leak somewhere but I'm unable to find anything, all lines seem to be well capped or going where they need to be, and when removed there is vacuum felt on the tube.  It would be odd for the Haltech built in MAP to be faulty, the GTT tune I imported had it enabled from the start, I incorrectly assumed it was reading a signal from the stock MAP, but that doesn't exist.  After running a vacuum hose to the ECU the signal doesn't change more than 0.2 in either direction.   I'll probably upload a video of my settings tomorrow, as it stands I'm able to daily drive, but getting stuttering when giving it gas from idle, so pulling away from lights is a slow process of revving it up and feathering the clutch until its moving, then it will accelerate fine.  It sounds like I need to get to the bottom of the manifold pressure issue, but the ignition timing section is most intimidating to me and will probably let a pro do that part.  Tomorrow I'll try a different vacuum line to T off of, with any luck I selected one that was already bypassed during the DBW swap.  (edit: I went out and did it right now, the line I had chosen did appear to have no vacuum on it, it used to go to the front of the intake, I've now completely blocked that one off at the bracket that holds several vacuum lines by the firewall.  I T'd into the vacuum line that goes from that bracket to the vacuum pump at the front of the car, but no change in the MAP readings).  Using the new vacuum line that has obvious vacuum on the hose, im still only getting readings between -6.0 and -5.2.  I'm wondering why the ECU was detecting -5.3 when nothing was connected to the MAP nipple and ECU MAP selected as the source. @feartherb26  I do have +T in the works but wanted to wait until Spring to start with that swap since this is my good winter AWD vehicle.  When removing the butterfly, did it leave a bunch of holes in the manifold that you needed to plug?  I thought about removing it but assumed it would be a mess.   I notice no difference when capping the vacuum line to it or letting it do its thing.  This whole thing has convinced me to just get a forward facing manifold when the time comes though.
    • Update: tested my spark plugs that are supposed to be 5ohms with a 10% deviation and one gave me a 0 ohms reading and the rest were 3.9ohm<, so one bad and the others on their way out.
×
×
  • Create New...