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Discussion Starter #1
I have an 03 fx45 with 221k on the clock with a goal of hitting 300k!

Just recently I started to have trans issues. Cold trans, no issues. But once I’ve driven around for a while, it seems the car doesn’t want to downshift into 1st. So when I take off from a stop, it’s very slow to get it going... once it gets up to speed, everything is normal. This gets me thinking it’s fluid issues (I’ve never replaced it)... on the other hand, I’ll turn the car off at a light and turn it back on and it starts off in first, so now I’m thinking it’s some sensor issue.

Anyone have any ideas? Also, any instructions on how to do a trans fluid replacement on this car?
 

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Discussion Starter #2
I also have a check engine light. My elm obd2 scanner kept saying no codes stored so i finally took it to autozone. They read the ecu and printed out P1759 and P1757. Searching around, it seems people are having issues with the valve body but Im hoping thats not the case for me. Also, Im read on the forums that theres no drain plug on this pan and ill need to drop the pan to change the fluid... however, i got under the car and there was a drain plug! I soaked the **** out of it with sea foam and the rusty plug came out fairly easy. Im using a 7qt drain pan and its mostly full from the drain but I think i read most people saying 4qts would come out, maybe misinformation similar to the car not having a drain plug.

Anyone do this and can speak to how much fluid came out? Im worried that 7qt is too much and perhaps coolant got into it. Also, when i do a fill, what fluid do you guys use? lastly, with 220 on the clock, im debating if i play with fire and attempt to pull the rusty pan to replace the filter
 

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You are correct in replacing the fluid before doing anything else.

I strongly recommend Amsoil Signature Series ATF. Magic in a bottle. But before you install the Amsoil you should have a shop do a full flush/fill with their machine plus the filter. If you ask nicely they'll fill your tranny with your premium Amsoil ATF.

This fluid has solved problems for me that has caused others to replace their trannies.

https://www.amsoil.com/shop/by-product/transmission-fluid/automatic/
 

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With so many miles on this trans and never having really changed the oil before, i definitely wont be doing a flush!

I did suck it up a couple nights ago and dropped the pan and changed the filer. Luckily it all went smoothly. I filled the car back up with valvoline where the label said its suitable for matic j and s and also added a bottle of Lucas trans slip oil. Upon startup, the difference was noticable. Prior to the oil change, the car would jump into gear when going from P to R. Now it slides in really smoothly. I havent driven it much the last couple days but so far so good. Hopefully this is the end of my trans issues for a while and this thread helps someone else with the same issues so they dont spend a fortune on valve body work which may not be necessary
 

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Idemitsu is the only one who makes a direct and qualified replacement fluid for our Trans. Bought it from a local auto parts store who had to order it in.... I did the same as you, draining all I could and refilling. I think it will add at least 50-100K to my tranny total life... Knock on wood, mine still runs great !
 

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Discussion Starter #6
Update: After driving the car for a week, the trans issues were back. I had the codes checked and it was coming back with:
P1759 A/T FR/B Solenoid Valve Performance
P1757 A/T FR/B Solenoid Valve Circuit Performance


I decided to take it back apart, this time pulling out the entire valve body. I pulled all the solenoids off, they all ohm'd out in spec. I applied 12v to the front brake and it clicked just fine. I then tested the leads on the TCU and they all ohm'd out so there wasnt any breaks in the leads. I ordered replacement solenoids off amazon and put them in and re-assembled the car. Took it for a spin last night and so far so good. I guess as I log more miles on it, ill see if this issue comes back.
 

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Discussion Starter #7
Its been a month and several hundred miles later. The issue hasnt come back and the car is still shifting great. I think we can consider this solved. Im not sure if the replacement solenoids did the trick or me cleaning out the existing VB and TCU with contact cleaner. For anyone in the same boat, heres the ones I got from amazon that are working


[ame]https://www.amazon.com/GooDeal-Transmission-Control-Solenoid-Pathfinder/dp/B01NBR7PE8/ref=sr_1_5?crid=CW5V9YRMLW8&keywords=re5r05a+solenoid+kit&qid=1573245811&sprefix=re5r05a+sol%2Caps%2C193&sr=8-5[/ame]
 
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