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Tps Problems! Solved By Unplugging A Plug?

adoboy666

By adoboy666,
in General Maintenance

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adoboy666 Community Regular

adoboy666

Posted
Posted

hey guys ive been having troubles with my car which would rev and stay at 1500rpm at idle and would sometimes act normal and idle at around 600-800rpm

when driving the car and revving it it would seem to bounce around with the revs every now and then and would lose power every now and then like i turned off the engine, although it wouldn't stall it would be revving up to 3000rpm then would just cut out and drop to 1000rpm then it seemed like the motor would just kick back in and it could rev again

i hooked my stock ecu up to the laptop with my consult cable and found i had ecu error code 43- throttle position sensor i logged the throttle position sensor voltage output which changes from 0.6v closed throttle to 4V full throttle and when the car started jerking the throttle voltage output would go to 0.0V.

After getting a second hand tps from the wreckers it did the same thing, so back to the wreckers i went and got another one which again did the same thing

now today i had a play with it and it seems that the car hasnt been showing the symptons yet since i have unplugged the big chunky plug with wires that come out of the bottom of the tps

anyone know wat this plug is outlined in the pic with the red arrow? does it go 2 the automatic transmission ecu or something as my car was once an automatic now manual

oh and the sealant was on my old old tps which i thought i could fix with sealant

post-36737-1247633041_thumb.jpg

DanShirts Collaborator

DanShirts

Posted
Posted

That's the TPS signal wire. The other connector on the TPS (the one that you've glued back together) is the throttle switch, it only signals open/close.

You didn't post what motor your working on. This my best guess based on my cars. The factory service manual is your friend.

  • 1 month later...
adoboy666 Community Regular

adoboy666

Posted
  • Author
Posted

nizzpro said that my idling issues were from the aac valve which is screwed

although that doesnt explain why my car jerks and the tps voltage drops to 0 volts

may buy a new tps from nissan, does anyone know what they are worth brand new?

mosquitocoils Veteran

mosquitocoils

Posted
Posted (edited)

I'll split my post into two parts.

THEORY:

Didn't you already try two TPS from wreckers and you still had the same problems? I wouldn't go buying a brand new one just yet.

Follow the AAC valve clean + idle reset in the tutorials section. I did it last weekend and now have no problems with erratic revs/dropped revs.

While doing it, you are meant to unplug your TPS and see if the revs change, if it makes any difference then it means the RPM screw on your ECU needs to also be adjusted. If the RPM stays the same when you unplug your TPS, then it's assumed your ECU RPM screw is set properly (I think that's what it all means).

SOLUTION (Possible):

I think you should try that AAC clean, disconnect your battery (and put your brake pedal down, to release any residual charge) reconnect battery (this resets your ECU) set your idle screw on your AAC to about 750-900, then unplug TPS and see what happens. Then try and set your ECU RPM screw to the same 750-900. Reconnect TPS - hopefully the revs will stay the same.

Report back mate.

Edited by mosquitocoils
mad082 Grand Master

mad082

Posted
Posted
I'll split my post into two parts.

THEORY:

Didn't you already try two TPS from wreckers and you still had the same problems? I wouldn't go buying a brand new one just yet.

Follow the AAC valve clean + idle reset in the tutorials section. I did it last weekend and now have no problems with erratic revs/dropped revs.

While doing it, you are meant to unplug your TPS and see if the revs change, if it makes any difference then it means the RPM screw on your ECU needs to also be adjusted. If the RPM stays the same when you unplug your TPS, then it's assumed your ECU RPM screw is set properly (I think that's what it all means).

SOLUTION (Possible):

I think you should try that AAC clean, disconnect your battery (and put your brake pedal down, to release any residual charge) reconnect battery (this resets your ECU) set your idle screw on your AAC to about 750-900, then unplug TPS and see what happens. Then try and set your ECU RPM screw to the same 750-900. Reconnect TPS - hopefully the revs will stay the same.

Report back mate.

since he has a consult cable he can do all of that much more easily through a consult program without losing all of his settings in his stereo, LOL. also he can put the car into base idle mode with the consult without having to unplug anything.

  • Like 1
adoboy666 Community Regular

adoboy666

Posted
  • Author
Posted (edited)

Thanks to everyone who helped me in this thread for all your help have solved the problem and has been working sweet for the past 2 days

first things first throughout this whole ordeal the tps error code 43 was showing up until i fixed it

ok here is wat i did

When i had went to nizzpro and got the diagnosis of the faulty aac (although they didnt notice the tps error code)they swapped the actual bronze/zinc coloured aac valve (not the whole unit just the valve motor that has the brown plug on it) over they just unscrewed the old one and screwed the new one in even though it was a new aac motor it still would rev at 1500rpm so they unplugged it and said i could drive like that

the jerking still happened so recently i swapped my whole aac valve unit over to an rb20det unit, i ran new hoses as the rb25de one has different hose outlets to the rb20 one

plugged it all in started the engine and again the engine was revving at 1500rpm even with the idle screw screwed in all the way btw i was doing ecu resets to see if that fixed it but it didnt

This made me think it cant be the aac thats causing the jerking and have read here that when ur tps screws up it makes the aac valve open up and rev between 1500-2000rpm

This confused me as the 2 main things that could be causing it have been swapped and the problem still occurred

So to the nissan workshop manual i went (for the 100th time uggh)

it said things in the manual about doing "active tests" on the aac valve which u can do with the software i have and the consult cable hooked to the laptop

with the software u can open the aac valve by adjusting the motors open rate which i did and found when it was on zero the aac was closed and made the revs drop to 750rpm and when i put it on max the aac opened up and revved at 2200rpm

this meant the aac was in working order i tested the original rb25de aac and confirmed this worked to so i swapped it back to as soo i could put all the original aac air hoses back on

after doing these tests and swapping the aac over i started the engine without the active tests going and was looking at all the sensor data on the laptop

the tps voltage which was set to 0.6V was bouncing from 0v to 0.3V (i thought sweet its at zero volts with the car stopped now i can bust out the multimeter)

i turned the motor off and started it back up, the motor was revving at 1500rpm and i found the tps volts where at zero showing that when the tps shows zero volts the aac opens up and makes the engine rev to 1500rpm

so out came the multimeter to check the signal plug wires at the tps, which were in order of 5v power signal and ground

i found that there was no power at 0V signal and did an ohm test on the ground to find it at 0.02

i took off all the earth wires on the motor sanded them with sandpaper and where they bolted to to get a good connection

rechecked the ohms from the sensor ground and through different points on the engine which showed 0.00 meaning it had no resistance which was great now into the car i went with the laptop in the passenger seat watching the laptop which still showed 0V signal coming from the tps so i had a look at the ecu main plug i put an extra earth cable to the tps ground at the ecu end and while moving the ecu wires to find it (the ignition was on) i could here a click from a solenoid (meaning wires were connecting and disconnecting from the ecu from bad connections)

the ecu plug was bolted in but the edges of the plug where higher then it was at the middle of the plug where the bolt was

so undid the bolt a bit pushed the edges of the plug into the ecu while doing the bolt up and presto the laptop showed 0.6V on the tps

i reset the ecu again started the motor which idled at 750rpm!!! i tested the aac by turning on all the lights the idle went down to 600rpm then shot up to 750rpm from the aac adjusting meaning it was in perfect working order

So after all that hassle it was just the ecu plug not having a good connection, maybe the cleanup of the connection grounds helped to

ive been driving this for 2 days and NO HESITATION NO JERKING AND NO 1500RPM IDLE HAS APPEARED

im stoked and proud of the work i did and glad that the software had active tests in it i was just about to fork over $216 to nissan for a new Throttle position sensor as well

IF ANYONE HAS BEEN HAVING THE SIMILAR SYMPTONS I HAVE eg hesitiation jerking or high idle and has the tps error code showing up at the ecu JUST PM ME AND ILL BE HAPPY TO HELP

Edited by adoboy666
mad082 Grand Master

mad082

Posted
Posted

ahahaha, i had a similar issue when i put a emanage ultimate in a mates 33. was running the car with it plugged in, then turned the car off to dick around for a bit with some settings, went to start the car again, nothing. wouldn't turn over. dash lights came on but that was it. tried to roll start it, still wouldn't go. got a new battery, still nothing. got it towed back to my place, decided to unplug the emanage harness and just use the stock ecu and it started first go and ran like a dream. then went to turn the key off and happened to bump the harness as i was doing so (was in the passenger seat and leaning over to turn the key off and bumped the harness with my foot) and the car stopped. plugged the emanage back in, made sure the harness was in at the sides and it started again.

  • 8 years later...

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