I have a 95 Honda Accord 4dr LX with the 4 speed automatic transmission. I had a crack in my plastic radiator so I changed it out with a steel radiator. I also changed the thermostat while I was at it. My transmission was working fine up until the swap, but now it will not shift out of firstand sometimes it won'teven go into gear. I have already tried changing the transmission fluid, and I read in another thread to check the solenoids and the line pressures. How do I check the line pressure and solenoids? Any help would be greatly appreciated, even if you can just point me in the right direction. Thanks.

 

Since everything else has been checked or changed, I would check the A/T Control Unit. You have symptoms as described here. http://techauto.te.funpic.org/transmission.php"The trans won't shift into gear or may get stuck in a certain gear."