At Solenoid

[tattoopops]

Hi, I am new to this forum and this is my first post. I want to know if anyone can tell me the exact location of the transmission AT solenoid on my 1995 Infinity Q45? Thank you

[goody90q45]

Connectors for the external AT sensors are located in a bundle at the aft end of the transmission where it joins the drive shaft. If you're having shifting problems the AT section of your FSM has instructions for a transmission self-check while sitting in the driver's seat as well as ohm testing procedures for the external sensors if their code comes up.

http://www.nicoclub.com/FSM/Q45/1995_Q45/1995_Q45/

What problems are you having with your transmission?

[elwesso]

There are many solenoids in the transmission.. I believe the TC Lockup solenoid is the only one you can access with the pan off, else the valve body needs to come out...

But like goody said, if theres an electrical problem it will show up with a TRANSMISSION MALFUNCTION on the digital display on the instrument cluster... and there is a self diagnosis procedure to find out what the issue is, if anything..

Usually the trans are pretty electronically solid, but just get tired after years of abuse.

[tattoopops]

I have a 1995 Infinity Q45. If I am at a dead stop and I accelerate rapidly the transmission shifts solidly-as it does pretty much all the time. Also, the transmission seems perfect sometimes but not others. It was shifting rough but I changed the transmission screen and fluid. When I did this it was a great improvement. At certain times such as slowing down, corners, or at slower speeds sometimes the transmission acts as if it is slipping or has hang time in it or that something keeps moving when it shouldnt be. Thank you, John

[elwesso]

I deleted your other post... You should just add a reply to the thread you already made....

Anyway, what is the exact description of the "solenoid" you bought. As said earlier, there are lots of solenoids inside the trans.

[tattoopops]

Sorry, I am new at this. The solenoid switch is small short-but kinda thick like a jumbo hotdog-cylinder that looks to be stainless. It has a small to medium size connector that is sort of a rust color. It has one wire that seems black. It attaches thru a small bracket with three holes possibly for mounting. I am confident it is an internal part because of its shape and a small plunger/screened filter looking tube that comes out of one end. Hope that can help you help me. I took a pic of it at hotmail and on my phone; just let me know. Thank you

[elwesso]

You can email me a picture and I'll take a look at it... Im more/less asking what was the description when you bought it, where did you buy it, etc... Theres lots of missing data that needs to be filled in before you start taking your transmission apart..

[goody90q45]

Does it look anything like this (revolution sensor?)?



Or this (turbine revolution sensor)?



We're ready for another clue. How about the 10 digit part # and the part name from the label (AT Sensor?)

[tattoopops]

It came from BestSourceAutoParts.com. On the invoice are two part numbers: 1-3194041x10, and 2-j4006131595. If you tell me how to attach a pic I will do it. Thank you

[elwesso]

just email me the picture, thats going to be the easiest way..

[tattoopops]

I dont know how

[goody90q45]

To post a pic in your thread it's got to be hosted on the internet first (google picasa, yahoo, etc) It sounds like you've got the picture hosted on the internet at hotmail so open the pic, right click and copy its properties (URL), then start your next post in this thread using the POST REPLY button, not the QUICK REPLY button. Once there you'll see a IMG button, click on it and [img][img] will appear in your post. Put the cursor in the middle and paste the photo's properties that you copied earlier. It's easy to do yet tough to figure out the first time. After that you'll be an expert at posting pics.

Or.... you can email the pic to Wes at [email protected] and he'll post it for you.

Was your sensor one of the two that I posted a pic of?

[tattoopops]

no

[tattoopops]

did you get this pic? I will also email to your friend. Thank you, John

[elwesso]

I got your picture, and it appears to be the line pressure solenoid... What im lost about is why you bought it and who told you this would fix your issue...

[tattoopops]

I posted an advice wanted ad on craigslist and then I described the problem and I received the following response: im not too familiar with infiniti but it sounds like your torque converter lockup solenoid is stuck or malfunctioned, sometimes a quick fix is to unplug the sensor which is probably why it was unplugged, it would give you a check engine light either at certain speeds or all the time, what happens sometimes is the lockup solenoid ( might be called something different on infiniti ) gets your transmission stuck in a higher gear when you are slowing down which would explain the hang time and the slipping at lower speeds, its almost like when you have a standard transmission and you try to start it off in 3rd gear but yours is opposite you're decelerating in a higher gear, if it were my car i would unplug the sensor again, being infiniti its probably a dealer only part and its probably crazy expensive"...The man that sent me this message referred me to this site and he forwarded me a picture of the exact solenoid that I sent to you and the information that was attached to the pic represented it as an At Solenoid.

[elwesso]

Well ok things are starting to make a bit more sense... I want to focus on the symptoms..

If the lockup solenoid is not working the torque converter would not lock up.. I'm not sure what you're prowess on cars are, so if this above you're level forgive me..

ON an automatic transmission, the torque converter basically acts the same thing as a clutch on an MT car... It allows the engine to rotate at a faster speed than the transmission, which makes it possible for the engine to be running while the car is in great... Essentially the torque converter is always slipping until you achieve lock-up... This means that the engine is directly coupled to the transmission..

Anyway, Its hard to tell if the converter is locking up unless you know exactly what to look for and what its supposed to do... The best way you can tell if the converter is locked up if you're driving on the freeway (say above 55MPH at a steady cruise) and slowly give it gas, the RPMs and MPH should increase at roughly the same rate, meaning the tach moves similar to the speedo, kind of like the engine and trans are directly hooked together..

I want to know some more history on this issue... Is this car new to you, when did this start???

[tattoopops]

I am a pretty good backyard mechanic; I replaced the transmission screen, fluid, and added an external transmission cooler last week; I can do brake jobs, tuneups and stuff like that to give you an idea of my ability as a mechanic it pretty much ends there. As far as the car I just purchased it a couple of months ago. Just so you know the issue only happens at very low speeds , corners, down speeds act. Can you tell me how I can install my part since I purchased it and to return it by mail to this company will cost me about $20. and it only cost $86.?????Thank you, John

[elwesso]

http://www.nicoclub.com/FSM/Q45/1994_Q45/at.pdf

Start at page 106. The lockup solenoid is on the lower side I believe, so you shouldnt need to drop the valve body. Page 34 shows where the lockup solenoid is..

Let us know if it does anything... I dont think it will.

[tattoopops]

Elwesso, you mentioned that you received the pic and that it was a "line pressure solenoid and then you asked why I bought it. Then when I explained, you said it made sense and you started talking about the lockup solenoid which is what I thought/think is wrong with my car. I guess I am a little confused now so I want to ask you what was the part that I sent you a pic of? Was it the lockup solenoid or a line pressure solenoid or are they one and a same? Thank you, John

[tattoopops]

Can anyone answer this question: Is a lockup solenoid and a line pressure solenoid different or are they one and a same? Thank you, John

[Lokim]

Line pressure governs when lockup occurs; the lockup solenoid controls the torque converter clutch operation. There are more solenoids in your transmission, but they are shift solenoids. So a lockup solenoid is a line pressure solenoid specifically for the torque converter's lockup function. The shift solenoids are line pressure solenoids for shifting from 1-2, 2-3, 3-4. Inside the transmission pan are 4 solenoids. They mount to the upper valve body. I don't know offhand whether they are accessible w/o removing the lower valve body. There is a 3-unit solenoid assembly, and a single solenoid next to those. The FSM nomenclature for it is the "line pressure solenoid valve." That is the part I think you're talking about.

Go here: http://www.nicoclub.com/FSM/Q45/1994_Q45/at.pdf and download the AT section. Look at page AT-132