P0740 2000 Civic EX D16Y8

[Ruumiskai]

So trans was replaced by previous owner. First time I got this code I tried to ask what the trans came out of but got ghosted. Anyway, the code only comes up if you drive between 55-65mph-ish , under 55 you're fine, over 65 also fine. I can mostly avoid driving between 55-65 but it's annoying. So if anyone's got any ideas outside of a new trans I'm all ears lol. Prob unrelated but I'm planning on replacing the trans dipstick too because it just sits there all wobbly.

 

[Brak]

I'm sure you looked it up, but P0740 is a transmission solenoid error (typically)

What exactly is it doing? not shifting properly?
I assume you've checked the fluid level while the engine is running, and hot?
remember, over full is worse than slightly low.

In regards to the dipstick, you want Part Number 25610-P4R-A01

I bought this exact one last year, came in honda packaging, and fit perfectly...
https://www.amazon.com/gp/product/B00BFDG17M?ie=UTF8&psc=1

That being said, if your dipstick is loose, there's a chance there is a bunch of water in your trans.
especially if you regularly use a car wash with the under car sprayers...
There was in mine.

 

[Brak]

here's a thread that might be helpful

https://www.civicforums.com/forums/332-transmission/381471-p0740-code-solved.html

 

[Ruumiskai]

I'm sure you looked it up, but P0740 is a transmission solenoid error (typically)

What exactly is it doing? not shifting properly?
I assume you've checked the fluid level while the engine is running, and hot?
remember, over full is worse than slightly low.

In regards to the dipstick, you want Part Number 25610-P4R-A01

I bought this exact one last year, came in honda packaging, and fit perfectly...
https://www.amazon.com/gp/product/B00BFDG17M?ie=UTF8&psc=1

That being said, if your dipstick is loose, there's a chance there is a bunch of water in your trans.
especially if you regularly use a car wash with the under car sprayers...
There was in mine.

It shifts beautifully, as long as you don't linger between 55-65. If you do it pops the code and then struggles with 4th. If you pass by 55-65 it shifts into 4th flawlessly (like while entering an interstate). No car washes, too many carefully placed zipties around the bumpers by previous owner lmfao. Honestly they are nearly invisible, i was impressed. Fluid looks pristine. Thanks for the part number autozones website naturally had the wrong one.

 

[Brak]

Just a tip. hondapartsnow has all the diagrams, to look up the correct part numbers.
Many oem parts are still available.