Codes P0730 and P0795, transmission not shifting properly

2003 HONDA CRV
220,000 MILES • 4 CYL • 4WD • AUTOMATIC
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MIKE WORTHY
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The issue started off just slipping when going from second to third gear. Checked the transmission fluid and it was kind of low, so I added some Lucas stop slip fluid into transmission. Needless to say this didn't help either, and here recently it's got worse! It shifts fine from first to second, but from second to third it's like the gear won't engage and it's in neutral, then eventually it will finally pop into gear. This has caused the check engine light to come on and the "D" light blinks.
This particular car has three shift solenoids which I changed all three. I also tested the solenoids by applying 12-volts to the pins socket and you are able to here the solenoids actuate like they should. I even changed out the clutch pressure switch thinking this was the issue but my luck it wasn't. I did have the codes for the check engine light read and it came up with two codes, P0730 and P0795.
P0730 came up as incorrect gear ratio and P0795 came up as pressure control solenoid c.
I don't know what else to try. Please help with any advice.
May 20, 2022 at 9:15 PM
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MIKE WORTHY
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I also drained and replaced with new transmission fluid and still the same thing.
May 21, 2022 at 2:38 PM
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KASEKENNY
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Unfortunately, I suspect you are going to need to replace the transmission.

These two codes are pretty clear and what they mean is that the transmission is trying to shift into a specific gear, and it is just not doing it.

Add that to the slipping that you are feeling then that means the internal of the transmission (clutches) have failed and require replacement.

Clearly, we should make sure the fluid is full, but it sounds like you have that covered already.

https://www.2carpros.com/articles/how-to-check-and-add-transmission-fluid

Basically, it is not able to engage the gear that is being commanded.

There is a chance that it is a fuse issue or other issue that is talked about in the info attached but again, when you have slipping as well as these codes, then that points pretty much to needing to replace the unit.

Take a look at the attached documents and let me know if you have questions.

Thanks
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May 21, 2022 at 5:04 PM
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MIKE WORTHY
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Kenny thanks for your reply, I was advised to change these solenoids but I think I needed to change the shift valves

What are these that I provided photos of?
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May 21, 2022 at 8:29 PM
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KASEKENNY
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These are your transmission clutch control solenoids. Based on the testing you need to change the first picture which is B and C that come as a set.

I would agree that these should be changed but normally when these solenoids change you don't have gear engagement. The fact that you are getting the attempt to engage but it is slipping points to a clutch issue which means the solenoids will not fix it. However, since the testing says to just replace them and retest then it is worth a try.

I attached the info below on these.
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May 22, 2022 at 5:23 AM
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MIKE WORTHY
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Thanks again Kenny k for the advice. I've tried everything except switching out the transmission. Today I changed out the shift solenoid valves, all four of them and still the same results. so, I guess new transmission it is!! Thanks again for all the helpful advice. I was wishing something minor would solve the issue.
The photo provided is the last thing I changed inside the transmission.
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May 22, 2022 at 4:24 PM
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MIKE WORTHY
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It is possible a transmission flush might work / help.
If so, how is that done or what solution is needed to perform the flush?
May 22, 2022 at 4:26 PM
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KASEKENNY
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Okay. That is good info. Sorry for the delay.

Unfortunately, if you changed these out and still have the same thing then it is an internal issue that you will need to replace the unit.

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

I am attaching the process to replace the fluid if you want to try it, but I doubt it will work. However, fluid is cheaper than a unit so if you want to try it then that is fine.
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May 23, 2022 at 6:34 PM