I have a '01 Accord with a v6 and a 4-speed auto, the shifting in the upper gears is solid, but the shift from 1-2 is very hesitant (it lets the RPMs get up to 3500 sometimes) and jerks a bit when it finally shifts. I've heard this can be due to a failing shift control solenoid. I was thinking of just replacing it, but I'm not sure which solenoid it is. Any idea which one that is?

 

Verify there are no stored codes in the PCM. Not all trouble codes will trip the CEL or D4 lamp to illuminate or blink.
Common problem with the ATs on the 98-02 cars I4 or V6 is that the 2nd/3rd gear pressure switches leak or stick.
This can cause a harsh 1-2 and/or 2-3 shift with a delay.

Shift solenoids rarely go bad. These can easily be checked by applying direct battery power to each shift solenoid(not the Linear valves 'H' shaped), they will have an audible 'click' when powered on/off. If not, remove and check the screen is not gummed up nor the pintle valve is varnished over. Use cleaner into the shift solenoid port to verify it is clean. If the valve still sticks or does not have a precise 'click' when exercised replace.