Transmission swap early model 2002 Q45

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Artillery155
Posts: 4
Joined: Thu Apr 20, 2017 7:38 am
Car: 2002 Q45
Location: St. Louis

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I have a 2002 Q45 with the early version transmission in it. I am not sure what significance this has except when I priced a replacement it was always a question of what month the car was manufactured. My question though is: Will the transmission from a 2003 Q45 fit or do I have to buy one that is specifically for that earlier date of this Gen of Q45? I found a whole car, only missing the front clip, with a good transmission for $800 plus all the other misc parts i could rob off of it over time if i desired or I can buy the transmission alone from a place online that will run me around $600 delivered but as I said that is the transmission for the early dates for the 2002 model year Q45's so I know it will work.


EdBwoy
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I assume the change in the q45 was as it happened in the 2003-2004 m45 world, that is the transmission stopped upshifting for you.
In the later models, if you started off from a stop in manual mode, the car would hold 1st gear until you remembered to upshift...etc, unlike the 1st year that will go to the next gear automatically.

Now, I believe at minimum you will need the TCU, but I don't know how much else would be involved in making it compatible. Not sure what communication the ECU would need to send. Maybe the FSM would say.

*Also, check the wiring. In my 2006 M45, which was a non-up shifting transmission, the trans had only one harness going into it from the main loom. I know the 2003 (auto-upshifting) had more than one plug. I considered "upgrading" but I knew wiring would be a mess, plus the wires didn't seem to be equal in number or coloring.
This might be something you can also verify from the FSM, but just ask for pictures where the wires go into the trans.

Artillery155
Posts: 4
Joined: Thu Apr 20, 2017 7:38 am
Car: 2002 Q45
Location: St. Louis

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I would have the complete 2003 so I could rob any parts I needed. I assume the TCU from the 03 would swap in place with the old one in the 02? or was it a redesign and i'll be making a place for it now?

EdBwoy
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I'm not sure about that, but in my experience with Nissans, they're averse to making changes for the sake of change. Most things are compatible over different years and models.

What happened to your transmission? This is not a common failure item to these cars.

Artillery155
Posts: 4
Joined: Thu Apr 20, 2017 7:38 am
Car: 2002 Q45
Location: St. Louis

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245,000 miles on it from driving my 80 mile commute to work every day and then my 16 year old took over driving it to school every day and after a few months of him driving it has no reverse or forward gears. started slipping a little then went quick. I am going to assume that he was being a typical teenager and tried showing off and just pushed it too hard. He says he didn't and I got a snapshot from progressive and installed it and it never registered a hard brake or fast accel when he was driving so idk maybe it was just time. a quarter million miles ain't bad i guess.

EdBwoy
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Maybe that's all it is after all. I can dig around the FSM a little later to try figure out the trans+component compatibility matters.

Is the 03 q45 located close by? Maybe you could just look at the trans plug to know what kind of work to expect. I'd say if the trans plug is different, then we're looking at pulling the entire engine control harness from the ECU back. Not too terrible of a job, but a headache anyone could do without.
This is the 06 m45 trans. The first year had maybe 3 plugs in place of this one, and the 06 q45 trans I saw on ebay seems to be similar to mine. I have no idea what an 03 one looks like, but this is what you want to avoid.
Image
Image

I am located in Belleville, IL so if the stars align I could swing by and take a look.

Artillery155
Posts: 4
Joined: Thu Apr 20, 2017 7:38 am
Car: 2002 Q45
Location: St. Louis

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I will see if i can take a look at it. it's located in the breckenridge hills area of STL.

EdBwoy
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Finally found some old pictures of my 03 M45 trans. This is the visible physical difference:
Image

Image


What you can't see is that the 06 M45 trans has its TCU/ TCM attached to the valve body in the unit.
The 03 M45 TCU is a dry unit and is located inside the vehicle.

kram7211
Posts: 5
Joined: Thu May 09, 2019 12:00 am
Car: 2016 Nissan Quest SV
2002 Infiniti Q45

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Did you ever swap out the 2003 transmission into the 2002? Did it work?

HollywoodJackson
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Joined: Thu Oct 23, 2014 1:35 pm
Car: 2004 Infiniti G35
1990 Nissan 240SX Hatchback
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I’m curious as well!


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