Rep Power: 0

Hi,
So I've got a 2008 Civic EX with 4cyl 1.8L automatic transmission. The tranny started to fail so I purchased a used replacement with only 63,000 miles that came with a 1 year warranty as well. It appeared to be in excellent condition. I used the official Honda Service Manual (from Honda) to swap it out, then filled it with Genuine Honda transmission fluid. When I went to test drive the car, there was no reverse. I let it idle for 5 minutes or so to give the fluid time to reach all areas inside the transmission, and then drove it. As I accelerated past 35 MPH, it dropped into neutral. When I revved the motor to assure myself it was a neutral drop out, it shifted back into drive and the drive light started blinking. I'm assuming it put itself into "limp home mode" because then I could accelerate without issue, but it stayed in D3. It also hard shifted when slowing down. I got an ODB2 scanner and it's throwing TONS of DTC codes! Mainly;
P0102 = Mass Air Flow sensor-low voltage
P1780 = Problem in Shift Control System
P0751 = Shift Solenoid Valve A Stuck OFF
P0752 = Shift Solenoid Valve A Stuck ON
P0756 = Shift Solenoid Valve B Stuck OFF
P0761 = Shift Solenoid Valve C Stuck OFF
P1746 = Problem in Shift Control System; Cut A Valve Stuck OFF
P0796 = A/T Clutch Pressure Control Solenoid Valve C Stuck OFF

I don't think it was done throwing out codes yet but I had seen enough. I THOROUGHLY went over the entire engine checking my work, disconnecting/reconnecting all the electrical connections, I had cleaned all of the ground connections the 1st time around, I used my multi-meter and verified voltage supply to hot lead of each connection, and verified ground at all locations on the frame, engine, and transmission. there was not 1/10th of a Volt drop anywhere.
So I'm at my wits end! I have no idea what the issue could be. It's obviously not a mechanical problem. The Honda Service Manual starts off every one of the DTC Troubleshooting pages for these codes with "Connect the Honda Diagnostic System (HDS) to the Data Link Connector (DLC)".
I don't have the money to take my car to the dealership to have them connect to the HDS and tell me whats wrong.

Anybody have any ideas???

 
Rep Power: 228

Perhaps it's a rebuilt case and hearing, using non OEM sensors?

You could try checking a few of the sensors to see if you can find

-honda
-denso (OEM part)
-or a serial code

Any possiblity of fluid, like coolant being left inside a plug? Perhaps check a few to see if they're dry.

 
Rep Power: 0

The transmission case didn't appear to have ever been separated when I was looking it over. Also, all of the plugs/connections are clean and dry, no broken or frayed wires/pins either. It's a really strange problem for sure. I appreciate you taking the time to help.

 
Rep Power: 0

This is an old thread now, sorry, but did you end up finding a solution? Please respond...

 
Rep Power: 0

HI everyone, 1st I'd like to say thank you to all who responded to my post. Next I'll explain what I ended up doing.
I hadn't put the new torque converter in when I swapped the transmission, thinking the original was fine. Once I had all these problems, I began to think I should have replaced it after all, so I did. Nothing changed. I pulled the transmission for the 3rd time and took it back to the yard I bought it from and they went to great lengths to get me the lowest mileage transmission they had in stocks. I installed it in record time this round! This time all the gears worked correctly! However, I still had an error code for low fluid pressure even though the level of transmission fluid was perfect. I also was getting the mass air flow sensor error code still. I replaced both the MAF Sensor and the transmission fluid pressure sensor and VOILA! No more errors and the transmission worked fine.
Neither the guys at the parts yard or I ever expected that the 1st tranny would be bad, (especially seeing that it had clean fluid in it) but it was. And I NEVER would have guessed that the MAF sensor would fail at exactly the same time that the transmission did, but that also was true.