'01 Q45 slow 2-3 shift

[lakeq45]

We have a Q45 we recently purchased used. Absolutely love the car, but it has a very slow 2-3 shift. The motor does not race or anything that would indicate a slip. The car shifts out of 2nd. Hesitates. Then seems to half shift into 3rd for a second or 2 with slight acceleration and then finally continues accelerating as usual. The problem is most common when the trans is cold, but will intermittently do it even when warmed up.

I have been told by my local Infinity shop that this is "Normal for this car" which I do not find comforting, since this is a true statement even if it is common for the trans to fall out of 01 Q45's. While I don't think the trans is in danger of falling out, this is not the first car I have had and would hardly call taking a countable number of seconds to shift "normal" behavior.

Of course, this problem did not show up until about a month after we purchased it, making me think the dealer may have added a trans additive to smooth things out in the short term. I did have the trans fluid changed a few months ago, which helped a little, but the problem has returned. We did purchase an extended waranty, so I would not have a probllem with a trans replacement just wanting to know if that is the best route.

Anyone else having these issues?

[jamesmost]

try another dealor dont beat a dead horse.dont go to corporate yet that can sometimes backfire

[maxnix]

There is an recent extensive thread on this by GQJay.

Fortunately, I don't have this problem.

A little maintenance history may be enlightening. ATF, filter mechanical replacement with a pan drop/wipe recently? Start there if you haven't already performed same.

http://www.bgfindashop.com

[FarFetched]

I have the same problem with my 97 Q45. Most likely it is a 2-3 shift solenoid modulating slower than it should. I bet, if there was a program to re-program TCU that problem would have been solved!Sometimes it feels like 2-3 up shift is "slipping" only if I catch it at sertain throttle position!

I don't think it should be like that. I can only wait to see what happens!my OldLady has 116K mile on the clock!

[3Q Jay]

lake, welcome to the home of Q45--both 1st and now 2nd gen.

as Brian alludes, this is pretty common on all but the best maintianed re4r03a trannies. [btw, my 97 shifts great--bought with 78k and the fluid was only brown--not black].

part of the reason for the slow shift is inherent in the design-- the 2-->3 requires the 'intermediate band'--wink to the other guy here who knows C6 trans--to release 2nd gear, while simutaneously [really quick sequential]engaging the high clutch for 3rd.

my $0.02 is exploit your extended warranty. if you want to try some stopgaps, i'll try my best to help--but if your unit has been abused, then nothing short of a rebuild can put back friction material in the high clutch.

Petr- have you thought about dropping your vb and doing the solenoids? that's on my to do list....

[FarFetched]

I'll wait till it drops dead and build one up with performance parts and new front pump (increased pressure). 2-3 upshift is exaclty as you say on C6 however C6 is all hydro unit!And if brake band is fried, you will get the same result (delayed shift). one thing though, fluid will burn fast(er) and (I know A4OD does have that "indicator") you can "smell" transmission because it's overheating!I know neq Q45 (particulary 2002) have similar problem with shifting. Infiniti came up with TCU upgrade which fixes the "bug".I don't have trans mulfunction indicator. I guess I should try "resistor" trick as you described in one of your pistings!Quote »I performed a little experiment this evening with the line pressure solenoid.- After looking at the wiring diagram for the TCU, I noticed that there is a resistor between one leg of the line pressure solenoid and ground. This resistor (I assume, not 100% sure) reduces the power draw of the solenoid. I do know that the way the resistor is wired in the circuit holds the solenoid slightly open even when the TCU wants the valve closed, reducing line pressure slightly.

I figured that disconnecting the resistor would increase line pressure since the solenoid can close all the way. Conveniently, the resistor is mounted to the inner fender behind the battery where it's easy to get to. I unplugged it and went for a test drive.

The result?

The 1-2 shift was HARD, like neck-snappingly hard. The 2-3 shift was perfect - fast and no delay.

The TCU caught on to the disconnected resistor, and gave me a "Transmission Malfunction", so I plugged it back in.

Anyway, this points even more to the slow 2-3 shift being the result of a lazy line pressure solenoid and/or sloppy TCU programming that lets the 2-3 shift take way too long. The first could be cured with a new solenoid pack, the second by possibly modifying the value of the solenoid resistor.

After my little experiment, I did some web searching and came up with this link:

http://www.smallcar.com/svx/tsk.htm

(remember the Subaru SVX shares the same basic transmission). This replaces the resistor by a variable resistor that is sensitive to engine manifold pressure.......[/quote]

[FarFetched]

Sorry, it was RobertsnewQ post...

[3Q Jay]

yeah, i know the fsm shows the dropping resistor on the '97 just as for the first gen, but i haven't gone and looked to see if it's in the same place [low on pass side inner fenderwell]. on the active, i'm presently running a 68ohm 10watt in place of the factory one. best compromise on 1-2 not breaking things and 2-3 being passible if not completely firm.

[FarFetched]

So what was the original resistor rate (OEM) ?

[jamesmost]

his car is still warrenty has to find a dealor willing to go for it , or corporate

[elwesso]

So what was the original resistor rate (OEM) ?

I tested mine as about 12.7 ohms.

[3Q Jay]

Petr-finally got to checking the '97 and the resistor is indeed there, nested between the coolant tank and the ps reservoir. has the 'jecs' logo on it.

lake- if you are still reading this thread, you can try unplugging that resistor [caution: this is at your own risk as it may add stress to the trans control unit] temporarily, and go for a quick drive. if your 2-3 shift snaps off, then you may be able to trim the resistor as a band-aid.

[FarFetched]

Thanks a lot!I get some free time and I'll dig in it!Cheers!

[FarFetched]

I've tried the "resistor" trick. I am sure A solenoid is faulty or/and valve in valve body sticking/leaking some!. I got almost perfect shift with exception of 2-3. It was a lot better, but there was a delay (very short) which made me thinking that it is solenoid rather than bands and clutches. I could take it apart and inspect solenoids (maybe even replace). I am too lazy to do that So I'll wait till it craps out and then deal with it!Cheers!