Under hard acceleration the transmission shifts out of the high gear but not into the lower gear and the engine rpms will red line if you don't get your foot out of the throttle.

Once you ease up enough the transmission will finish the down shift.

1) Replaced the speed sensor per error code. No Change but the error code never returned.

2) Checked ohms and applied power to the Solenoids. Both sets in spec.

3) Replaced ECU. No Change.

No error codes of any kind are being generated.

I'm afraid maybe it's something mechanical, like a valve, sticking in the transmission. But for now it is a mystery to me. If anyone has any suggestions I'd like to figure this out.

Thanks,

Steve

 

Have you check your ATF level? what ATF are you using? you know most drivers only use Honda ATF in their honda tranny right?

 

The ATF fluid level is good. Genuine Honda ATF fluid.

The problem showed up suddenly one about a week ago.

 

Your transmission is slipping and in need of a rebuild. Just like a manual transmission, eventually the clutch packs wear out and need to be replaced.

 

I know what a manual transmission feels like when the clutch slips. Why does this automatic not feel similar?

It locks up fine on the up shift it feels like it slips into neutral on the down shift.

I've never had an automatic transmission fail so maybe I don't know what failing clutch pack on an automatic feel like.

It doesn't feel like slippage it feels like non shifting. Is there some kind of way to diagnose it as a clutch pack definitively?

 

Well this aught to be fun... Pulling the transmission since it won't go anywhere now.

I'm going to take a shot at rebuilding the transmission but once I most likely fail at that endeavor will end up with used one. lol.

holmesandmanny you are probably correct. I'll keep everyone posted on the result.

 

It is way harder to rebuild an auto than a manual. It might be wiser to have a reputable company like Synchrotech do the actual rebuild after you pull the tranny.

 

Most likely what happened is the sump pickup has become full of junk and the transmission is simply starved of fluid.
You can try draining and refiling the sump with a hydraulic cleaner to break down the gunk, but most likely it is impacted too much already.
If the transmission is making loud whining sounds with the engine running, you are most likely hearing the AT pump cavitating, no fluid flow, no go.

Sump filter is not serviceable, only way to access it is to open the case. At that point you may as well rebuild it.

 

Just wondering.
Did you ever check or adjust the tranny throttle cable?

 

The cable checked out good. :-/

 

Here's the post mortem...

Unfortunately none of the low hanging fruit applied to this transmission failure. The educated guess is that the old transmission had clogged filter. Since the filter is on the inside it would basically require the old transmission to be rebuilt anyway. So I purchased a rebuild with a 2 year warranty, installed it and am back on the road.

So it goes. :-|

 

The same thing happens to me in my car, were you able to fix it?