# Pathfinder issues..tps/trans



## Bedore (Feb 26, 2011)

Greetings,

I am having some problems with a 1999 Pathfinder, 182k miles. The TPS trouble code appeared and the TPS was replaced with a new OEM units, and supposedly adjusted correctly. Although code P0120 is still in the computer. That said, the garage is now saying the transmission is failing. Heres whats happening:

Going down the road it will sometimes shift fine, sometimes bump when it shifts, but always shifts. When you give it some fuel to accelerate, the RPM's jump way up to 4k and there is no power until you hit 4.5k+ RPM's and then it will start to accelerate. You can hold the pedal to the floor and it will continue to accelerate all the way till it hits the rev limiter, but does not shift. If you let off on the gas, the RPMs will return to normal (2k or so around 55-60). If you press the accelerator again, nothing happens and the RPMs will jump way up and as I said before, but nothing will happen until 4.5k RPMs or so.

Any ideas what is going on? It runs great otherwise. Is the transmission failing? Anyone else encounter this?

Thanks.


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## smj999smj (Jan 1, 2006)

Was the TPS code erased initially after replacing the TPS? If it was and the code has returned---and assuming it was properly adjusted---a scantool should be used to graph the TPS signal while slowly depressing the accellerator pedal to the floor, checking for a clean signal without any breaks. Hard to say if the trans is failing without knowing more about the TPS circuit and testing done to it. The only tell-tale sign of the trans failing at this point would be inspecting the fluid for burning, debis and metal specs.


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## Bedore (Feb 26, 2011)

smj999smj said:


> Was the TPS code erased initially after replacing the TPS? If it was and the code has returned---and assuming it was properly adjusted---a scantool should be used to graph the TPS signal while slowly depressing the accellerator pedal to the floor, checking for a clean signal without any breaks. Hard to say if the trans is failing without knowing more about the TPS circuit and testing done to it. The only tell-tale sign of the trans failing at this point would be inspecting the fluid for burning, debis and metal specs.


My thoughts as well. I took my handheld scantool and cleared the code out just now. Took it down the street and within a minute the CEL came on. Has two codes stored, both are P0120 TPS codes. Does anyone have the proper procedure for adjustment? It's my sisters rig and she has had it at 3 garages now, and 3 different TPS units (1 original, 1 aftermarket, and 1 OEM which is on it now). Could the TPS being out of adjustment cause the issue with the trans?


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## Bedore (Feb 26, 2011)

Well the TPS issue has been resolved and the CEL does not come on. However the transmission problems are still present. It seems to shift into second fine, but likes to stay in second, and when you give it gas the RPMs will jump to 4k or so before you get any power. Then it stays around 4-5k rpm's. Is the transmission slipping? Is it safe to assume that the transmission is going, or is it still something electronic? The pan was dropped and the filter and fluid was replaced (not a flush, just a drain/refill), and nothing looked out of the ordinary.

Any help is appreciated.


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## villapath (Apr 7, 2011)

Was having a similar problem with my '98 pathfinder and wanted to know what you found out on yours.


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## pf99 (Apr 14, 2011)

Idling and shifting on my 1999 pathfinder had been very rough recently after it warmed up. Changing motor oil and transmission fluid did not help.

The garage told me the idling control valve had to be replaced but pointed me to the TPS instead. While we are still trying to figure out what to replace, I adjusted my TPS last weekend back home, before I found this pdf on the web today:

http://www.google.com/url?sa=t&sour...sg=AFQjCNF5hm0pMh9cPpXOe0ZPI0HmaISNnA&cad=rja

Without any instructions, I got mine to almost smooth by trial and error. It still has a little hesitation on acceleration after a complete stop, but there is a huge difference already. Perhaps I'll try again to get rid of that little hesitation with a multimeter and filler plates following the instructions. The close throttle position may be still a bit off.

I haven't replaced nor ordered the TPS yet. I am not sure what is really faulty.

Good luck.


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## pf99 (Apr 14, 2011)

A little update to my post:

The variable resistor in my TPS was really jumping all over the place at some bad spots when I put my multimeter on it. 

I bought a new TPS online and replaced it on my own. It's exactly the same Hitachi.

Hope this new one would last. Another 5 years should be good enough as the rest could rust out by then. (We use lot of salt in winter here.)

It looks like my car is back to normal for now. I am still waiting for my ebay OBD USB cable to arrive so that I can check/reset the error codes.

Cheers.


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## pf99 (Apr 14, 2011)

The check engine soon light went off on its own. By the time I received my OBD2 reader, the history had gone or I don't know how to get to it. Hence I can only tell my pathfinder is back to normal and nothing more.


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## villapath (Apr 7, 2011)

*Hows your pathfinder running?*

I have put two-three TPS on my pathfinder in the last two to three years. I haven't had any trouble out of my pathfinder for almost a year or so (up to 320,000 miles). Now it has started to run rough. It is sputtering now when I take off from a complete stop. I have replaced the spark plugs and wires. I am going to replace a few other items. In the back of my mind, I am wondering if it is the TPS again. The Hitachi has been going bad on several that I bought although on this last one it has lasted longer than I thought. The TPS has saved me on several occasions because I was told I had transmission problems and need transmission work. At one time, the faulty TPS caused some serious jerking.


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## pf99 (Apr 14, 2011)

The TPS is a dumb variable resistor, it should not fail too often. 

Replacing the TPS requires calibration of of the zero throttle position. The tricky thing is that fast idling may add throttle for us when it is cold. The procedure calls for setting the fast idle gap to a certain width. 

I did it myself and I don't really have the filler gauge, hence the calibration is kind of an approximation. And we are also supposed to thread lock ths TPS so that the setting would drift over time. 

It has been 3 years since my last post, the TPS is still OK on our 1999 pathfinder. 

Starting at very cold days, the first shift into gear is usually a bit rough without warming up, probably because it wasn't warm enough or the gap wasn't exactly right when I did the calibration in April 2011. 

After warming up a bit shifting is fine. Unfortunately my wife and I usually just start and go, no matter how cold it is, otherwise we won't notice the first rough shift. 

Please check the calibration first, your TPS may still be OK. When the shifting is done at the wrong throttle it may seem like a transmission problem. 

Good luck.


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## billhappy (Jun 14, 2015)

Hello everyone


Has any one actually performed the procedure mentioned in pf99 's post, dated 4-14-2011 ? There is a google link highlighted in blue it is in post six of ten. I would also put that link here in this post but I don't know how to do that. The reference is For Throttle Position Sensor . " NTB99-053b " I ask this question as I have now tried to do this procedure with my old tps and a new tps oem from rock auto. Would really like to talk with someone about this procedure. Thanks in advance Billhappy


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## pf99 (Apr 14, 2011)

TPS is still OK. My wife got a smaller car for summer, we store our 1999 pathfinder every summer now to save gas.


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## billhappy (Jun 14, 2015)

Hello pf99

Thank you for your reply. Glad things are okay with your rig. I guess the question I should of asked is why I don't seem to be able get the desired ohms reading, referred to in the bulletin and has anybody else, using that procedure.


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## billhappy (Jun 14, 2015)

After posting this last post I noticed that I,m growing in status . I am now a Sorta Newbie Thank you also much


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## smj999smj (Jan 1, 2006)

billhappy said:


> Hello pf99
> 
> Thank you for your reply. Glad things are okay with your rig. I guess the question I should of asked is why I don't seem to be able get the desired ohms reading, referred to in the bulletin and has anybody else, using that procedure.


Make sure you do the procedure with the engine fully warmed up and also that there is no varnish build-up inside the throttle body keeping the throttle plate from fully closing.


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## billhappy (Jun 14, 2015)

Hello SMJ999SMJ

Thanks for your quick reply.
I did not only have engine warmed up but checked fsm from NissanHelp.com about fast idle cam adjustment and completed that adjustment also. Yes I thoroughly cleaned throttle plate bore there was little dirt if any . AS you know I did replace tps with a new one.
I have many questions regarding this whole repair as I'm also getting code p1605 p0325 0302 0731 . In another post you had mentioned a service bulletin that instructs people to replace the a/t control module , I bring this up as I took the shift solenoids out of valve body and bench tested them according to fsm . Tcc Line pressure solenoids fine a, b and clutch over run solenoids no audible click when 12 volts applied. Do you know if it's the failure of a/tcm causing those three solenoids to fail or was it coincidence it was about the same time? Or visa-versa? 
AS far as the p0302 it is intermittent sometimes after trying to adjust the tps the next time I start vehicle the miss is nonexistent.

AS far as p0325 I went ahead and removed every thing and ohms tested knock sensor, 580 ohms, according to the Haynes manual it is fine. p0731 I've replaced tps confirmed o/d light circuit is fine . I'm having trouble confirming inhibitor test as the color of wires in my rig don't match schematic. And there seems to be an extra pin in the smaller of the two connectors that go to my inhibitor switch.
Gee aren't you glad you replied to this post , Any and all help would be greatly appreciated . Sincerely The pathfinder from HE double hockey sticks aka Billhappy 
P.S. Codes 0731 and 0302 did not show up until after I did the ohms test procedure.


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## billhappy (Jun 14, 2015)

Hello again SMJ999SMJ

Thought I should have shared that the vehicle will not shift into third gear and that the rpms on tach are 3000 to3400 @ 55 mph
depending on the day. The gas mileage is horrible to say the least and it was the poor mpg that brought this whole issue to light.
Initially I thought the poor mpg was due to I was doing some fairly heavy towing for a few months.


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## smj999smj (Jan 1, 2006)

The TCM replacement was only for the early years of the R50, I think 96 and 97? Nissan never explained why it was to be replaced but it had nothing to do with making the solenoids fail. I wouldn't worry about the knock sensor code, especially since you have an intermittent misfire of cylinder #2. All I can say as far as the solenoids is that if they don't pass the test per the service manual, you would be best to replace them. They come as a solenoid pack assembly. When it comes to checking wiring circuits, the diagram will usually show the wiring colors of the main harness, not necessarily those of the component's subharness. You should also be aware that there were two service manual for the 99 model year, as it was a "split year" model. Early '99 models had VIN #'s "up to -350000" and '99.5 models had VIN #'s "-350000 and up." You may be looking at the wrong service manual for your vehicle.


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## billhappy (Jun 14, 2015)

Hello smj999smj

I am remiss in taking so long to reply and post . Thank you for your quick reply as usual . After reading your reply I thought I should share that it is a 1997 pathfinder not a 1999 model. Since your reply I thought yeah I would do well to replace the transmission solenoids, so
back to the pick-apart salvage yard. I have now pulled solenoids from 7 pathfinders from 1997 to 2003 and every one, the same results.
The overrun clutch solenoid makes that familiar click when voltage is applied and a,b,c solenoids don't. What I didn't mention in the last communication is that last fall I tested solenoids brand new in the box and got the same results. I bring this up as I'm hard pressed to believe that all the solenoid sets that I pulled and tested were bad in light of the exact same results on a brand new set of solenoids. 
I'm wondering if I'm misunderstanding something in the test procedure . Respectfully billhappy


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## Jsim444 (Jan 22, 2016)

I have found that three of the solenoids are not spring return.
In other words they click one time and then something must push them back into position before they will fire again.
I took a paper clip and very gently pushed the plunger back.(couldn't even feel it move)
Then I left the paper clip in the hole and applied 12 volts and the solenoid pushed the clip right out and onto the table.
So I figured it was good and that it had to have hydraulic pressure to make it reset.
The TCC and the other solenoid (the one that is separate from the 3 pack) are spring returned and I could hear them moving every time that I applied voltage.

I have a 99 pathfinder that I replaced the distributor on (would not crank) It cranked right up afterwards, but I removed the TPS to get to the bolt easier. Then It will not shift into higher gears. I adjusted the TPS and still had the shifting problems. I got a P0744 torque converter clutch circuit intermittent. I cleared it but have not gotten the code to come back. I guess I have not driven it enough. I have checked the wiring from the TCP to the solenoids, and the wiring from the TPS to the TCM. I not checked any wiring to or from the ECM. The TPS show steady output when my scanner is connected.


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## Jsim444 (Jan 22, 2016)

I have checked the wiring from the {TCP} to the solenoids. TCP should have been TPS, oops... Proof read, me never.LOL


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