I've got a 2001 accord 3.0L automatic with a B7XA transmission 165k on it. I'm throwing a p0780 code and p0505 I have just bought this car. I put new motor mounts, plugs. New tranny fluid ( just drain and refill) new solenoids ( leniar shift solenoid and shift lock up solenoid) still have to do the shift solenoids in the front.

My problem is obviously the codes but when I put my transmission in gear the car stalls, I put my A/C on and did the same thing. No stall.... my D4 light is blinking and car is in limp mode. I'm waiting on the last 2 solenoids now. When I drove the car home it shifted pretty rough, but I attributed it to the motor mounts. Now it just in limp mode and I can't figure it out. As far as the p0505 code, it cant be the air idle control valve. I just put a new throttle body on there with all new sensors. It seems the more I fix the deeper I get Lol.

I've owned hondas before, I had 3 cb7's so I'm familiar with the cars, I'm just stumped with this and don't want to rebuild.the tranny. Any real help.will be appreciated. Thanx

 

I found that this video helped in where the solenoids were and how to check them

P0505 can also be a vacuum leak causing the issue for your idle.

To be quite frank, if it does need a transmission, you can get them pretty easily today off ebay or local scrapyards for not that much. I picked up one for $300 with a 90 day warranty not long ago and was offered one from the scrapyard for $150 with a 30 day warranty on it. Sold one not long ago to someone local for $200 in perfect shape.

Anyway, those are some thoughts.