Truck wont shift into 3-4. Stumped

[CanuckQx4]

Hey guys, Im over my head on this one and hope to repair it with the forums help before I brake down and bring it to a shop and eat Ramen noodles for a year. Luckily I dont need the truck so it can sit til I fix it.

It is a 2001.5 Qx4, has 120k on it. The problem seems to be transmission related but after some research there are so many things that can cause transmissions issues on this truck its crazy. Its very cold here in canada, which isnt helping. Just this weekend I did a full trans cooler flush with 20L of fresh DexIII and Lubegaurd red, fluid level is perfect.

Problem is when I start driving, it revs much to high shifting 1-2, and then just wont shift anymore. Kind of like a limp mode, luckily I only work 3miles from home and dont mind driving in 2nd @ 3k rpm and 35mph. it just wont shift, stays at that rpm, feels like the torque convertor isnt licking up and letting it shift.

Is there some sort of reset or relearns that I must do properly first?

Just 2 days ago I discoverred the PO had installed a Maxima MAF, but he gave me the OEM QX4 one in a box, I cleaned that one today with proper MAF cleaner and installed it, but it changed nothing. Possibly needs to reset ecu first?

On my way to work Im going to buy a fuel filter, but I was under the truck and the one currently installed doesnt look very old at all, its barely dirty which makes me think its almost new. But whatever its cheap and easy.

I know Im in deep with this problem, but I live in such a small town (no Nissan or Infinti dealers for a LONG ways) that I dont trust to take it to a local shop, I will honestly compensate a member or even a charity if they wish to help me fix this problem. Not even kidding, $100 anyone?

Hope someone has some experience to help me fix this, cheers guys

[CanuckQx4]

Just popped into my head after some researching aswell, this truck is actually LOWERRED using 4x4parts springs.

Could the driveshaft somehow be compressing to much and causing some sort of bind/trouble enough to cause this? I do believe my shaft to be in poor shape, but I did just grease its zerk with wheel bearing grease.

My truck being 2wd might be different than most here but that "troubleshoot" just popped in my head

Replaced fuel filter just now after work (3am so awesome), took it for a spin after a good warmup and it changed nothing.

I forgot to mention the car threw 2 codes the first day I had it on the road and this system was acting up to the point of not shifting. I believe it was P1744 (torque convertor) and also a rear 02 sensor code.

It threw the torque convertor code I blieve in the first few miles of the problem because i was reving the engine to high while driving to see if it would shift. I erased the code and have driven about 15miles since at a top speed of 40mph in second (to and from work twice) and that code has not returned. The code for the oxygen sensor did come back on within a few minutes, I forgot to write down the P # again for that but it was a rear 02 and Im assuming not a big problem or causing the truck not to shift

Also getting horrible gas mileage, appears to have used 1/4 tank in 40 miles, but I am cruising in 2nd gear

[Buzzman]

.....I do believe my shaft to be in poor shape, but I did just grease its zerk with wheel bearing grease.

Sounds bad.
I think they make a pill for that now though. (I believe it's blue in color.)

[Towncivilian]

A maladjusted TPS could be the cause of your problem. Try adjusting the closed throttle position according to the reference values on EC-108.

[CanuckQx4]

Im curious how that would mess up the D3 D4 shifting AT ALL, but I appreciate your knowledge soo much.

After reading EC108-110, have you seen the reset procedure for the tps? On 110, says you have to key OFF for 5 seconds, key ON for 10 seconds, TWENTY TIMES... seriously??

I have tried these "key on, key off" crazy procedures in the FSM before, and I never seem to have any sucess even when using a stopwatch, is there a trick to it?

[Brute 03]

I'm having a similar problem. Trans won't shift past 2nd until its warmed up a bit. I also don't have reverse until the truck has been running for a while. I'm not sure where to start since this is my first A/T car

[Towncivilian]

I'm having a similar problem. Trans won't shift past 2nd until its warmed up a bit. I also don't have reverse until the truck has been running for a while. I'm not sure where to start since this is my first A/T car

Check the fluid level and condition. If it's brown and/or smells burnt, it's time for a cooler line fluid exchange.

[CanuckQx4]

Adjusted the TPS, was slightly out. Did the reset procedure, still not shifting

Anything else cause no D3 or D4

[CanuckQx4]

And to be honest I dont even know if these procedures are working and reseting anything, for the 5 second key on, I do about 7 seconds (stop watch) and the 10 second key off, I do 13-15 seconds. Takes a while doing that 20+ times

I read the throttle valve closed reset procedure, which is much simpler, but states you should hear the throttle valve (no idea what they mean) move when the test is complete, but I hear nothing?? Is my car not taking to these resets? Would NOT doing the reset procedure after adjusting tps still cause it to not shift?

On a side note the car threw the P1446 code while test driving, evaporator code. So I'll have to fix that once this other problem hopefully is resolved.

What do you suggest I do?

[CanuckQx4]

I think my TPS may be faulty. Can anyone confirm if its the brown or grey connector that I am pinning to be adjusting the TPS?

For poops and giggles I decided to recheck the calibration after a test drive, and it is WAYYYY out, I couldnt get the meter to show continunity, so with the probes connected I had to manually open the throttle 3/4 before my meter beeped for continuity. Almost 40mm of movement where it only took 1mm before.

Somethings way off here, the manual isnt very "english" about which of the T/B connectors i am to probe, so Id like to sort that 100% before I go buy a new sensor from Nissan...

hopefully onto something!

my offer still stands for that crisp $100 bill! (via paypal hehe)

[Towncivilian]

Did you look at the pinout diagram on EC-170?

Our 2001.5s do not have any relearn procedures except for the idle air relearn as described in the FSM. Those 20 key-cycles are for drive-by-wire models apparently (2003-2004).

[CanuckQx4]

Im looking at the 2001.5 pathfinder fsm on this forum...

http://www.nicoclub.com/FSM/Pathfinder/ ... der/ec.pdf

EC-110 on that link shows the key cycles. Did they just label another year pathfinders manual as a 2001.5?

Id love a link to a version that matches yours for a 2001.5

But EC-170 does show the closed position sensor pinouts, but the diagram for #5/#6 (what im trying to test continuity on) is confusing how it is pictured isnt how it is mounted on the throttle body, its actually flipped 180*... which would change what pins Im probing

Wish they would also ink in which wire color leading to each # pin was, they probably do somewhere, I'll start hunting

[CanuckQx4]

After finding a labeled diagram of which connector the "throttle closed position switch" was with a lamens diagram showings its orientation on the engine *EC-178*, it is indeed flipped from how they show it on EC-170, and the correct pins to be testing for continuity while adjusting it are from the bottom connector when looking over the engine, testing the top 2 pins in that connector

I most likely was testing the wrong pins, will redo after some sleep

[Towncivilian]

Ah, my apologies, I didn't see that in the FSM since it wasn't under the table of contents as it is in the newer FSMs. That damn relearn procedure sure sounds like a headache - I'm afraid I don't know what to suggest to help complete it except that you don't have to be spot on with the 5 and 10 seconds it seems, as the FSM says "wait at least..." so maybe you could tack on a couple seconds each iteration and see if that will help. Also, are you trying to do the procedure when the engine is warmed up?

Good luck with the electrical testing!

[CanuckQx4]

Ya I was doing to relearn with the engine completely warmed up, but with it taking 10+ minutes after I shut the engine off with the car sitting outside in 30 degree weather, could it be cooling down to much??

Im gonna bundle up and head outside and probe this switch again and adjust! Hope it works

[CanuckQx4]

Sucessfully calibrated the TPS, after starting the truck to let it warm before preforming the relearn key cycles the car was idling @ 1200 fully warmed, and after doing the key cycles it idles at a perfect 750 so I think that worked great. I then triple checked the calibration test again, continuity with .002" feeler gauge, no continuity with .006" feeler.

Took her for a test drive, still didnt shift into 3-4

Is it possible the car wouldnt "learn" to shift and needs a full ecu reset?? I have yet to pull the negative cable for 24 hours... but I think im pulling at dead straws here

Is there anything else that would cause no D3-4, or am I fighting a lost cause and I need a transmission.

I also checked trans fluid again and its still in perfect level on the hot side, and fresh smelling.

[Towncivilian]

Based on AT-242, there doesn't seem to be much else you can easily look at... Since the fluid in there is spotless, the next step would be to try to reset the TCM and see what happens. Disconnect the negative battery terminal, step on the brake to dissipate any remaining residual charge, wait 5 min and connect it back and see what happens. Maybe you'll get a DTC this time.

Glad you were able to calibrate the TPS successfully!

[CanuckQx4]

Well my girlfriend is almost here to drive me to work so I will just disconnect the battery until I need to go to work tomorrow, about 22 hours, and see what happens. I also read about tapping the brake as you mentionned but the tech said that you disconnect the negative cable, then the positive cable, and actually touch the positive wire to the battery negative and then touch the brake to completely discharge.

I really dont feel it is a transmission issue for some reason, seems like a sensor... but Im not sure if an ECU complete reset would change anything here

The Infiniti dealership is about 45 minutes away, maybe an hour limping along in second gear, Id really hate to drop it off there and give them open forum on it, Ive never had to take a car to anyone to fix anything for me, so that kinda scares me

It just doesnt make sence for gear 3 and 4 to disappear

[CanuckQx4]

I found this thread. weird-noise-comming-from-transmission-t536749.html

They mention the transmission not shifting. And the P0740 type code that my car also threw once, so I think it is relevant, althoughI believe my code was P0741, but it may have been 40

"P0740 Torque Converter Clutch Solenoid Valve Circuit Open" code prevents lockup of the 4th gear when driving on the highway at speeds of over 55mph. I changed it out myself and was very easy to do. The testing of the solenoid is very simple too if you follow the procedures in the workshop manual. Once I tested mine it was bad and then I ordered it and replaced it. You can find it fairly cheap on ebay for around $80 shipped (l paid $160 for mine at the dealer"

Maybe I need to drop the pan and do some testing? Ive never had the pan off to see what is accesible or even there to know if I can test the solenoids. Im about to step out the door to so i'll have this on my mind all night.

[CanuckQx4]

Im also leary of the throttle switch position calibration, the manual is either mistaken or my sensor may be wrong. It shows pin 4/5/6 with the connector "tab" which is on the firewall side in the engine bay, so the correct pins to probe according to that would be the bottom 2

But when I did that on the car, the meter didnt show continuity until 3/4 throttle, so I assumed they were mistaken/ hard to decifer. When I probed the bottom 2 pins the test was easy to calibrate and the tps in good straight orientation. Is the sensor possibly bad?

Youve got the same 2wd engine Town, do you get what I mean about there diagrams being confusing, I posted the pages 2 posts up. Maybe I did the test right, maybe I didnt. Damnit

[Towncivilian]

Are you able to see the colors of the wires for each switch? EC-176 describes the throttle position sensor harness connector's pinout. That one is the topmost plug into the TPS; the other is the closed throttle position switch. I can understand the confusion regarding the testing procedure, but I think the color coded pinout should help clear things up.

The AT diagnosis process only references checking the sensor and not the closed throttle position switch, so we shouldn't need to check the lower harness, especially since your idle is spot on.

I'll look into the P0740 code and find the cheapest source for an OEM part. Hopefully you'll get some code after you reset the ECM/TCM so we have something else to go on.

[Towncivilian]

OK, so there's no P0741 code. You almost certainly had P0740 then.

Looks like you can check the valve's resistance without removing anything; see AT-151. Not sure which harness it wants you to check exactly since it references the transfer case and we don't have one. EL-411 tells you where harness connector B64 is, though.

If the valve checks out bad, looks like you have to drop the pan, remove the strainer, then the control valve assembly and you should have access to the solenoid. Looks tedious but not too difficult otherwise - see AT-273.

You can then test the valve by applying battery voltage to it and see if it clicks.

[CanuckQx4]

It was P0744, I dont know how I miswrote that.


Heres how I interpolated the fsm, and the wire colors as they are on my car

The orange/blue I wrote may be pink/blue.

I didnt want to attach the battery yet to redo the test to ensure I tested the top 2 wires when setting the switch calibration.

Pulling the transmission apart is probably over my head, as you can probably tell Im not as savvy with the fsm as I wish I was. If it came to that I may have to enlist a shop, or purchase a working used. But Im really hoping its something to do with a sensor etc

My obdII scan gauge arrives tomorrow finally from repair and I can monitor alot more than my ebay code eraser. I really hate to drive the truck while its not shifting, but I almost want to, to make it throw a code. The only time it threw the P0774 was the first day I drove the truck after insuring it for the winter, and I was revving the engine to 4500-5000 rpm wonderring why it wasnt shifting. I have been grannying it to work since, and only 20 miles total, so maybe it needs more time to throw a code... I dunno, gotta sleep

[Towncivilian]

OK, I went out and looked at my TPS connectors:

Top connector has a brown plug, and:
Pin 3 (this is the top pin, looking at the connector while it is still plugged in): Black with pink stripe
Pin 2: Red
Pin 1: Pink with black stripe

So, this top connector is the throttle position sensor harness connector, not the throttle position switch harness connector as shown in the FSM on page EC-170. EC-178 is correct, however.

Bottom connector has a gray plug, and:
Pin 6 (again, top pin when looking at the harness plugged in): Orange with blue stripe
Pin 5: Red with yellow stripe
Pin 4: Orange with black stripe

I hope that clears things up with the TPS.

P0744 looks much more involved and serious than P0740. If I follow the FSM correct, the solenoid valves the FSM wants you to test would be accessible after removing the control valve assembly, which involves removing 20 bolts which secure it after dropping the pan (the bolts have different lengths, but the FSM tells you where they all go). If you've done a pan drop before, you can remove the control valve assembly.

Of course, testing the two solenoid valves immediately would be jumping ahead a few steps - the FSM wants you to disassemble the control valve assembly and inspect some things and check for sticking valves (which hopefully there should be none given fresh fluid and Lubegard Red claims to help free sticky valves). Disassembling the control valve assembly looks pretty involved, and I wouldn't want to attempt it myself.

[CanuckQx4]

So i connected the battery this morning after nearly 2 days, started the truck up and it died, started again with a little throttle and it was idling real low. 525 rpm according to my ultragauge, took it for a spin and it still wasnt shifting. Idle fully warmed set at about 600rpm, so it looks like I may have to do the idle air relearn procedure.

One thing I should mention about the shifting, when the fluid is cold, and the gear selector in D while driving, the trans will shift 1-2 no problem, but once the fluid is warmed and you accelerate from a stop it is very hesitant to even shift into second gear. But if you move the gear selector to D2 while slowly accelerating, it will shift perfectly as you select it. Dont know if that gives anything away as far as possible symptoms

This moment I just finished installing the stock style exhaust, which will e great to hear myself think and what the car is doing lol. Then I'll tackel the driveshaft swap for an hour or so.

Dont really know where to go from here

[CanuckQx4]

Im not going to say I understand the FSM, because I really dont. But shift solenoid B comes up ALOT in the diagnosis of P0744. I see no real lamens diagrams of how to really access or test it though.

Im not sure if I should buy a used trans for $500 and hope I can change it myself. Or if this transmission is worth opening and replacing parts. Ive obviously never seen the inside of an automatic transmission. Ive rebuilt Honda engines before, but they dont seem near as complicated or electric dependant

I also dont want to depend on the code P0744 so much as it only triggerred once, and hasnt again, should I drive around in second gear for a period of time to see what errors are thrown or am I just causing more damage that way

[CanuckQx4]

I finally found some info on the PNP switch on AT-102 and a great component check on AT-103, but for the component check on 103, it says to check continuity between 1 and 2, and 3 and 4,5,6,7,8,9. I guess that means they SHOULD have continuity. It mentions moving the manual shaft through each position but I dont quite understand that.Looks quite difficult to diagnose but I will get the truck jacked up and get under there in the morning and see if I can figure out what there saying to check. Hope the connectors are easy to get to. Guess I'll just have to get under and find out

I did clean the transmission and pan right before taking the car out, maybe I bumped something out of position? Doubtful but Id really love to have this truck worry free!

[CanuckQx4]

I got the front end jacked up to look at the PNP switch and its connector, and wow is is ever tight there. Cant see the connectors at all, couldnt reach them if I wanted to. This problem is over my head.

Now here lies the problem, who do I enlist to fix it for me?

The car is a little modified, so Im not sure if that will shy shops away or cause problems.It has an AGM battery under the hood, with an unconventional "threaded" top terminal. And also multiple large gauge grounds in and to different places than OEM, obviously there upgrades for the stereo though. It has 2 extra Optima batteries in the trunk for my stereo, so there is 0 gauge fused power wires going to the front and back aswell. Electric fans deleted the factory thermal clutch fan.

Im not positive my transmission needs to be replaced at this point. So in that sence I think an Infiniti dealership would serve me well (would nissan dealership touch it?) as they could do a good diagnostic and probably pinpoint the problem accurately, as they built the car right But charge me $125 and hour...? And take 9 hours to change a shift solenoid, oem parts and labour add up quick

I can also try a well reviewed local transmission shop, but I fear they may not be specialized enough to diagnose and may be quick to sell me a complete transmission overhaul for $2,000, or is a transmission shop generally capable of maybe saving you some money...

I think i need to hire someone at this point though, I could always purchase a used low mileage transmission off ebay for about $600, pay someone $4-500 to install it. But thats a crapshoot with a lot of chance, hoping its something internally damaged

[Towncivilian]

I'd lean toward the dealership since they have CONSULT-II available. As long as you find a tech/dealer worth their salt and don't give up as soon as they find that there are no codes, hopefully they can determine the problem.

[CanuckQx4]

The consult II is a good point.

I came upon a reciept the PO paid $1300 for "transmission repair and labour" in the stack of papers from a local mainstream transmission shop, from 2.5 years ago. Its past the warranty implied on the invoice but maybe they will be able to say what was done or help for cheaper.

I think $1100 is the most id like to spend on any work/diagnostic on this transmission before buying a used one online with a short warranty