1999 Pathfinder P0744, no job, please give advice

[maniak262]

Hi,

I am new to these forums and need any information. I've searched the forums already but even the p0744 doesn't seem to completely match the symptoms I have. FIrst off I have 3 codes.

P0744 - A/T TCC Solenoid Valve Fault.
P0440 - Evap system leak.
P0325 - Knock sensor or circuit fault.

3.3L Motor w/ Automatic Transmission

I am PC Repair guy and have got my hands dirty in previous cars. I love my pathfinder and want it running good.
Currently it won't shift to the 4th gear. When driving it, it will take off and the RPMS will go high and I have to let off and press the gas again around 3k for it switch gears. This happens in both 2nd and 3rd gear and 4th gear never happens. I am more concerned about the transmission issue right now. I dont think the knock sensor or Evap leak would cause it and i'll address them later. Also, I completely drained the transmission fluid and replaced the filter and put some Lucas in it. Please someone help.

Thanks in advance.

[maniak262]

So far on a 2001 this is what I found.

1. Stuck TCC valve
2. Valve Body
3. Hydraulic circuit.
4. Solenoid

[Towncivilian]

What's the condition and level of the transmission fluid?

1. Drive around for 10 minutes in the city after the transmission is at operating temperature.
2. Park on level surface and apply parking brake.
3. With P selected, shift through every gear and return to P.
4. Pull transmission dipstick with engine idling, wipe clean, reinsert completely, and read level. It must be within the notched areas labeled "HOT". Check for fluid contamination after wiping on a paper towel.

The fluid should be reddish pink, and not smell burnt. If it is brown/black, smells burnt, or metal flakes are visible, do several drain & fills, each within a few days of each other (or do a pan drop).

For your EVAP code, buy a new OEM gas cap to begin with.

The knock sensor is a very difficult sensor to get to, it is below the lower intake manifold collector. Are you experiencing any knocking? Since your VG33 motor requires 87 octane, I wouldn't try jumping a grade of gasoline.

[qwertyz]

on your 440 code its going to be charcoal canister and vent valve 100% replaced a ton of them at work and or gas cap ^^^

on 744 Hydraulic Circuit, Torque Converter, Sticking Torque Converter Clutch (TCC) Apply Valve, Valve Body,
This code is not set due to an electrical problem. It sets when the Torque Converter Clutch (TCC) lockup solenoid
wascommanded on, but there was no RPM difference.
325 knock sensor (will not set ur check engine light on) but try better gas 93 octane, and if better gas dont help
replace sensor

[Towncivilian]

93 octane will do nothing for the knock sensor in his VG33, it's designed to run on regular and likely can't advance timing any more if using higher octane. It may even run worse, as higher octane fuel is more difficult to ignite.

[qwertyz]

than replace a sensor it only calls for 4.2 hrs

[maniak262]

Towncivilian: About 2 weeks ago I did a full pan drop as the transmission fluid was burnt looking. I replaced the filter then, added lucas(recoommended by friend) and filled the rest with regular transmission fluid. As far as flakes, I did notice on the pan it had a magnet that had alot on them, i cleaned it as well.

qwertyz: As far as the 440 code, i dont think that one has always been there so it may be the cap however I bought a used muffler/pipe set for 25$ a while back (mainly for the metal plating as mine rattled), it may have the charcoal on it...never replaced one of those but Iam sure I can figure it out. Also, the knock sensor, I found a Video on how to cut on a wire near the top of the motor and basically put the knock sensor above the motor. I was going to look into that after I get the thing to drive/shift right. I am worried about the transmission. I recently lost my job and my ex-boss is going to fight unemployment while iam looking for a job so I am Very poor with 2 children, one of which is going to school and this thing is eating gas like no other. My question. I have kept reading its the solenoids. I found the parts online, a Upper and Lower. One is 70$ and the other is 300$...could that be it and also, are they accessible from where i dropped the pan. I saw alot of stuff right there. I got a book and what not so I dont do stuff without knowing, just curious. I dont have alot of money to gamble stuff. Thats also why I can afford to drain and flush over and over. I mean, I did it once and saw no difference. Could that really be the cure? Not shooting down any advice though, I just have to borrow money to get it working and I get chewed every time.

Thank you all for your help so far, and once again, i know computers. So PM or reply here if you need help with a PC.

[Towncivilian]

Oh jeez, why did you add Lucas snot? I doubt it'll do much of anything. Use Lubegard if any transmission additive at all, they make the best stuff. What type of trans fluid did you use?

The knock sensor sounds like a fun job to me (not). The knock sensor for the VG33 is also ridiculously expensive. Maybe I'd unplug it and forget about it.

The muffler, etc should not throw a code to the best of my knowledge. The EVAP canister is in the rear of the vehicle, beneath the driver's side quarter panel (at least it is on my 2001). But as I said, buy a new OEM gas cap first and see if that solves it.

[maniak262]

lol, ya i would say screw the knock sensor but booo. I have emissions to pass. I dont remember what type of trans fluid. It was whatever the O'reily guy recommended.

[Towncivilian]

Well, okay. If you can afford it, do another drain & fill using Valvoline Maxlife in a day or two. The trans should take about 4 quarts for a drain & fill, verify afterwards with the dipstick of course. Do you have an Advance Auto Parts near you? They have extremely generous discount codes if ordered online then picked up in store - I would go that route for purchasing more transmission fluid. See here for codes. P20 takes 20% off anything except engine oil and some other stuff, no minimum amount if you can't find any better code.

[qwertyz]

don't worry about knock sensor if you fix other problem you will be ok, I repeat again IT WILL NOT SET YOUR CHECK ENGINE LIGHT ON
if you fix EVAP leak and your Trany code (Even if your ECM will see an engine knock IT WILL NOT SET A CHECK ENGINE LIGHT ON) you will still have a code but you will pass emission TRUST ME

on your evap leak, charcoal canister on driver side rear take it off, (4X10mm bolts 3 hoses and one electrical plug) take the vent solenoid off of it and see if you got any charcoal lose (if yes replace the canister if not you might be in luck) make sure the solenoid operates properly 2 wire plug basically + and - 12V if you apply 12v solenoid closes and you cant blow through it if it don't close after voltage applied it's bad

on your trany code (tough one cause i am not good with transmissions) take the pan down probably going to have to take the valve body down also and replace the torque converter solenoid (not sure where it is, but shouldn't be too deep in a trany) get a new part and go for it

[Towncivilian]

If you find that you need a new charcoal canister, a junkyard run will fix that for cheap. I believe qwertyz advise is good regarding testing the canister and the info about the knock sensor. I really don't know about the transmission, I'm just suggesting more fluid exchange because you said your trans fluid condition was not so great when you started. It can't hurt.

[ARKQX33V6]

Remove the rear canister and verify all hoses are connected, remove the rusted crap and check the valves also, examine the valve under the hood that initiates the canister. Pull the gas cap, look for dents, wipe clean and snug up the cap 2-3 clicks

Do not use anything but 87 grade gas, regular unleaded.

If you have been using high test it is likely that carbon has fouled the engine.

Check your intake manifold TPS throttle plate area for carbon fouling if it is blackened clean. A sticky gas peddle indicates carbon build up. Your EGR will need carbon dismantled from it also.

Transmission: The control valves, lock up valving from your description are possibly hanging up because of crap, magnetic holder at dump area indicates this..

Change out transmission oil, at least a drain of the sump, 4-6 liters and this time examine the pink fluid and feel for bits of dust size metal fragments and clutch material. The friction materials within the transmission may be too low or worn for a good traction grab and replacement may be due, or an adjustment.

Do not use Lucas treatment, the best treatment is a change of oil every 2 years.

Knock sensor, reset MIL and keep driving with regular fuel, if you want to pour something in the gas try marine 2 cycle oil as an upper lube at no more than 1 oz per gallon in the tank.

Examine the outside of transmission for leaks, especially the coolant lines heading to the radiator, they will leak at the banjo connection at the transmission,near the top.

Your TPS may be the cause of high revs in transmission, check that all auxiliary switches work along with the potentiometer for the throttle position and these have to be tested with the connection made and tested downstream.

When done, try operating that vehicle with a gentle right foot, can you get to 55 mph and use all gears and never turn the engine over 2000 RPM. If you are successful now try driving in all gears set in manual and listen feel, then place transmission in D and with a gentle foot go through the gears, gently then again hard, record all gear changes up and down and let us know.

By the way this set of guidelines are spelled out in the manual.

[Towncivilian]

I second the above suggestions. The ratio you quote for TC-W3 in the fuel tank (1 oz per gallon max) is too high; roughly 400:1 ratio is better. 1 oz per 5 gallons of fuel is an approximation. Too little will do nothing, too much may cause issues. You can read more about using TC-W3 with gas here.

Fuel system cleaners that contain poly-ether amines (PEA) such as Chevron Techron, Gumout w/ Regane are proven to be extremely effective at removing deposits without leaving residue of their own. BMW actually rebrands Techron as its own product. I'd suggest running a 20oz bottle of it; add it to a close to empty tank before filling. I think Advance Auto still has buy one get one free 20oz. Techron bottles.

If you feel the need to add anything in the transmission, use Lubegard Red. It's widely regarded by many transmission shops and users to be nothing but beneficial and it is very difficult if not impossible to overapplicate with this stuff.

[qwertyz]

why the fuel treatment????? ( I don't get it personally, what that got to do with trany evap and knock code, we all know that nissan knock sensors are junk that why nissan didn't even bother turning check engine light on when its bad)

throttle plate i agree, transmission agree also, evap like i said and like ARKQX33V6 said inspect the charcoal canister and or gas cap, Towncivilian got some good info also

after you check everything don't forget about feed back we would like to know what helped and what did not

[Towncivilian]

Poor fuel quality or heavy deposits in the fuel system (especially injectors) may be causing issues; if the knock sensor detects too much detonation, it will retard the timing IIRC. Either way, a known good fuel system cleaner can't do any harm.

[ARKQX33V6]

Remember we are all trying to advise you on a set of conditions that you have expressed. We are not there, so you must realize points of view from different people will reflect those different experiences.

Your fault codes are of a wide range and a code of itself must be looked at in its entirety. Surrounding things somewhat related could also trigger a set of events that may cause a code to appear.

Transmission codes related to gear ratios can be caused by the TPS switch which houses 2 other switches and throttle is related to fuel.

All in all the engine is a mass of parts that must be in synch with each other and the ECM tries to control all these parts and the transmission.

So as a diagnostician, you and I and several others must think in the box and outside the box, the obvious apparent broken part may not be the correct problem part, but maybe its the screw holding that part.

Along the way we have all discovered remedies that work, these tricks of the trade may or may not solve your particular difficulty, but these hints get tossed out and its up to you as to whether it is useful or not.

All in all help is here. Pathfinders and QX4 vehicle are not the best and not the worst, some of their designs will get you scratching your head, but over all they are a pretty good 4 x 4. In my experience with multi drive vehicles the 97 QX4 at 30 MPG imperial, highway and good wear at 240,000 km is not bad. The vehicle by nature is a rust bucket but that can be mitigated by under coating it every so often.

Some year cars seem to be prone to difficulties, some are not...

[yeldogt]

Whenever you get a evaporator code on an older car the most prudent thing is to check the hoses very carefully -- especially around the engine and anyplace that you may have recently worked. The hoses for the emission system are small and get brittle -- it does not take much to have them leak. Unfortunately the canisters do fail -- so it obviously could be that. On the 3.5 motor both of mine have had the small hoses on top of the motor fail and give me the evap code.

The antiknock sensors also fail. Unfortunately, they are not as easy to replace as the equally failure prone cam sensors -- so it is a little bit more of a problem. First -- are you hearing the engine "ping" under load? The use of high test is not going to increase carbon deposits -- what is that all about?? If you clear the codes and fill with higher octane gas and the code does not come back and then you fill with regular and it does -- it may be a situation that the engine is knocking and you do not hear it.

You don't indicate the miles on the truck -- the transmission is a more serious problem. It sounds like you may have more than one problem -- the massive slipping in the early shifts is an indication of a failing clutch pack and if it is not going into high gear that can be a couple of things -- non of them particularly good.

It is not unusual to find small metal particles in the sump magnet -- that is why it is installed - to catch them. It is very rare for a fluid change to solve a major transmission problem.

It is shocking how many people never check the fluid -- and low fluid is a major cause of transmission problems and failure. You should always always use the factory recommended fluid -- no additives are needed or recommended.

[Towncivilian]

As I said, higher octane gasoline takes more pressure to ignite. See article here. As to whether running unnecessarily high octane in a motor designed for 87 will produce more deposits, I'm not sure.

[yeldogt]

It is not that it takes more pressure to ignite ...it is that it will allow for more pressure before it will self ignite - you want the fuel to be ignited by the spark of the plug not the pressure and latent heat of the engine. The 3.5 motor is designed to produce max power using 93 fuel -- it is recommended that way in the manual. I have always used regular in mine and they run fine. Some cars designed for premium fuel will run fine with no ping without problems except for lower HP using regular -- others will not. It really depends on the setup of the engine and then the preference of the owner.

I own four cars that require premium: two will not run on regular -- one is fine with mid-grade. The final will run without pinging but the loss of power is noticeable and I only used it once for a test. We used to have a couple of Ford V8's in the company fleet that were designed to run on regular -- they pinged like crazy -- we had to use mid-grade or premium while other exact examples ran fine on 87?