1994 Infiniti Q45 Will Not Shift From Second (AUTOMATIC TRANSMISSION)

[KPotter]

Okay I got a 1994 Infiniti Q45 with 188,899 miles on it. Car runs very quiet and Smooth. Then today I noticed that while on the interstate the car never shifted out of 2nd gear. first works, second works, but 3rd, even if i manually put it into 3rd, it is the same as second. Then Drive, Is also the same as 2nd and 3rd except when I let off the gas in Drive its as if the car is in neutral and it begins to idle. Then when I give it more gas in drive, Its as if it is in neutral until a certain rpm. The gears are not slipping and have never slipped... The funny thing is, I have randomly seen a TRANSMISSION MALFUNCTION light on my diagnosis screen. Very rare, but it has happened about 20 times in about 6 months. But I ignored it, since it didn't happen that often, and I had no problems.

someone mentioned a TPS. What is this, what does it exactly do, and if this is the problem, how can I get it repaired as cheaply as possible...

Thanks a lot guys...

[94infinitiq45]

The same exact thing happened to me.Your transmission needs to be rebuilt it is the high clutches that go bad.I rebuilt mine myself for 300 bucks if you think your qualified then do it.It was harder to pull it out then it was to rebuild.I used the fsm which explained everything great.But if you aren't up for doing that then gettin a reman or one from a junkyard would be your best bet.

[KPotter]

How hard is it to rebuild. Where can you get the kit to rebuild it myself...

Thanks a lot for the info 94infinitiq45!
Modified by KPotter at 7:51 AM 7/28/2007

[JP500]

I had this happen to me a few times in my 94 Q45T. It started around 120K miles, and it would always happen on a certain incline. Eventually, it would shift into that 'next' gear, and then the problem would not occur for the rest of the drive. It always would happen ONE time every trip... very weird.

Then, magically, the problem stopped. Once every few months it does it again, but I can't justify a transmission rebuild -- if that's indeed what it would need -- on a car that has a trade in value of about $2K. I'll change the fluids per spec, rotate the tires, wash the exterior, and drive this thing until the wheels fall off and the rotors are bent. Unless your car is in exceptional condition, I'd recommend to do the same. Rust is beginning to form behind the rear wheels in mine, even though it's been garaged its whole life.

[elwesso]

if you're getting a transmission malfunction on your display you can check the codes on the computer.

http://www.nicoclub.com/articles.php?id=217453

Do that and report back.

[KPotter]

Well, the thing is that I dont get the message on the screen... I have randomly seen it pop up on there but its been a month or two since I seen it last. Even on days I did see it, I just restarted the car and it went away.

[KPotter]

could someone please give me some more info on what I should do... Rebuild? get new? If rebuild, where do I get parts? If get new, Where to get Trans...? Other possibilities that could cause my car to malfunction...

Thanks

[goody90q45]

could someone please give me some more info on what I should do... Thanks

Take the advice of the master (Wes) and complete the self-diagnosis he posted up for you first before you start thinking about replacement of the transmission. I did this self-test a couple of weekends ago for the first time and it's simple- takes less than 2 minutes. Everyone should do it. Post up the codes and you can go from there. Since I've had a similar problem to your's (only twice) I'm going to guess that you'll get code 1- Speed (revolution) sensor.

Next time it won't shift pull over, turn the engine off for a few seconds and then restart. Worked for me. Good luck.

[94infinitiq45]

Go to Phatg20.net or .com i cant remember.Look under fsm's &programs &user upload then go to fsm's and go to infiniti then to q45 and you'll see 94 is the first one download that.Then download winrar and adobe reader.After u do that open the fsm and go into the AT section and go to page 41 which is self diagnosis(without consult).Perform this then let everyone know.My car had no codes or anything so i knew it was something mechanical not electrical.It would shift 1-2 fine but would never leave 2nd.Let us know.

[94infinitiq45]

Also pull your dipstick and see if it smells disgusting and if it does then somethings definitely burnt up.If you cant really tell then drain the pan (about 4 qts) and if its black and has any different smell then new atf then somethings wrong.I could smell mine from the other side of my garage after i took it out.Which is about 20 feet.Lol good luck tho

[KPotter]

I ran the diagnosis by holding the trip reset button to the left when turning on the key... It gave me code 3. (Throttle position sensor) I cleaned my Throttle body since I needed to clean that anyway... And since I cleaned it, It gives me no codes. I tried holding it to the right when turning the key on and I did the same thing as I did in AT CHECK MODE (Put it drive before key is on, Put in third and depress accelerator and let off, went to second, then third and depress the accelerator and let off) When I did that, It switches from OK to Transmission Malfunction twice then a pause... The switches from OK to Transmission Malfunction nine times with the 8-9th time, It switched quicker than the rest. Then a pause. And keeps repeating the nine interval flash from OK to Transmission Malfunction. What exactly was it doing by holding it to the right... It shows (------------) scrolling down the screen, then (|) scrolling across the screen before it gives me the message...

Thanks a lot for trying to help me out... Its frustrating but worth it if I can get this thing fixed...

[KPotter]

Oh and I forgot to add that I do not see a check engine light or a malfunction while driving it... It never shifts from second, its not an intermittent problem it just stopped shifting all of a sudden... Thanks

[94infinitiq45]

Hmm I really have no idea but to tell you to look through the fsm and all that.Sorry i cant help ya. My car gives a code for the tps 2 sig which is the signal getting sent to the sensor that controls the blade for the tcs but i dont feel like looking for a short in the wire and my car runs fine and shifts fine and i've had the tps code for 7 months now.It is a different code then what you're getting though.

[Q45tech]

Normally when one has codes that don't clear or come back soon, the next step is to Connect a Consult [using transmission diagnosis mode] and analyse the situation further.

Owners must always be prepared for AT replacement after warranty.

In 315k I'm on the 2nd replacement unit and have a spare waiting, you never know when you will need to get dirty.

[KPotter]

Where can I get a rebuilt kit for under 500 dollars...94 Q45

thanks

[maxnix]

First, you have to define what the rebuild kit you want should include. Don't replace just one part, and the most worn one will limit the life of your rebuild.

Why the smart money gets the Nissan factory rebuilts from Joe.
Modified by maxnix at 2:52 PM 4/19/2008

[kpotter21]

ok, my q45 is sitting in my yard and it make me cry! I want to drive it but cant afford a new trany rigt now... It drives fine but will not shift past 2nd. runs great, just replaced fuel pump like a week before trany failure...

But i am wondering.... My check engin light isnt on, but when i take out the ecu and run it in diag mode, i get codes 34 and 43. (tps and knock sensor). Could this be the cause of my trany problems?

190,000 milesnew fule pump at 199,980trany fluid changeMAF replaced at 180,000trany fluid changed every 30,000 miles

It just quit shifting one day.... I was on the highway, it was shifting great... then i hit the gass enough to cause it to downshift to second and it never would shift out of second. If it were a trny problem, like a clutch, it would have been slipping for a while first.... but it never has...

HELP?

[Q45tech]

The AT requires an accurate TPS voltage level to know when to shift.

While KS won't illuminate check engine light TPS will unless bulb is missing or burned out.

KS will make car buck and snort under many load conditions.

Must keep everything functional.

The soft part tanny kits sell for $300-$450 from your wholesaler/transmission parts supplier.................but valve body and TC lock up clutch wear may mean hard part replacement.

I would fix and adjust TPS first.

[maxnix]

Rust is beginning to form behind the rear wheels in mine, even though it's been garaged its whole life.

All garages (especially heated ones) do is hasten the rate of corrosion once the car is subjected to winter streets with salt. It's actuallly better to leave the car out if it is not rinsed after every winter drive.

[kpotter21]

I tried to adjust it... just moving it and driving it but all i could accomplish is making it not even shift into second. but i put it back and it shifted into second. I check engin light isnt on, but if i adjust the tps way out of wack, shouldnt te light come on.... it doesnt. worth replacing? I just dont see how the trany would go out all of a sudden, w/no warning signs...

[goody90q45]

Check the CEL by turning the key to the ON position without starting the engine. All the warning lamps should illuminate for at least a couple of seconds.

[Q45tech]

You cannot adjust TPS without VOM to monitor voltage. Even a 0.1-0.2 volt misadjustment can cause shifting havoc depending.

Prior to 1996 engine warning light is very insensitive, all it shows are when sensors were totally disconnected [open or short circuit] or failed to provide a range of voltage [steady unchanging voltage].

OBD2 [1996 and later] are a little better a throw codes when sensors are outside of expected range by 50-100%.............when things are so bad that they might effect emission testing.

[kpotter21]

ok the check engin light works but doesnt come on... so does the tps have only two wires or more? and where can i find what the voltage should be?

Thanks alot for you help guys