This is my first post and I'll try to be as specific as I can but please bare with me. Keep in mind that I am on a shoestring budget, otherwise I would've taken my car to the pros. I have an 01 Honda Accord 3.0 V6 LX Coupe which I bought well used (and as is with automatic transmission and air conditioning problems) with 215,000 miles on it. The transmission after warming up, slips out of 2nd and into 3rd with a noticeable jerk and more often than not when trying to drive at freeway speeds (60 -70 mph) won't shift into 4th. I tried every type of variation of acceleration to coax it into fourth because I don't want to drive on the freeway continuously at 4000 plus rpm's. (Not to mention the gas mileage.) But to no avail until out of desperation at about 4500 rpm and 65 mph I quickly turned the ignition key off then on again and voíla... It smoothly shifted into fourth. I drove home from work at this speed for 45 minutes. But when I exited the freeway, came to a stop at a red light and tried to proceed, it was stuck in 3rd or fourth and accelerated very slowly... So I downshifted manually to second which did the trick. Any suggestions? (Besides getting rid of it) I paid very little for it but love the strong V6 V-Tec motor and want to keep it.

 

Beg/Borrow/Steal a proper OBDII scanner and check for any stored codes. Not all codes will set the CEL/D4 lamps to illuminate.

Main and or countershaft sensors may be dirty, shift solenoids sticking, pressure switches not functioning, or the gear shift range sensor may be dirty or faulty.
When the trans stayed in the higher gear the PCM is in limp mode. Engine running condition also affects transmission functionality.