only can start with obd2 plug in

i couldn't start my car this morning(crank but die right away). so i borrowed the obd2 from my friend. no code found when i plug in . the thing that weird is i can start the car with the obd2 plug in as soon as i unplug the car die right away....

spec :accord 96 ,AT

has any one experiance this problem before

pls help....................

I think I remember something like that...the eCM had lost it's ground, and couldn't work right, was pulling a ground through the diagnostic connector when the plug was in.

thanks jeffcoslacker ,you're totally right , first I tried to swap the pcm to my friend's car seems like my pcm was still good.
so i pulled out the obd2 link connector from my car. jumped between brown and black which is both are ground cable.
and start so perfect as before.........................

once again thanks to jeffcoslacker for the great info...