I shorted out the ECU plug as shown in Haynes manual and my D4 on the dash starts flasing a code 278 2 blink then 7 blink then 8 blink...then starts over. Now its flashing on the transmission selection area on dash NOT the check engine light!

What dose this mean? It has been shifting poorly and often. The car 93 EX only has 34,000 true miles??

 

im not sure about the tranny issue but you are not throwing code 278 tou are throwing codes 2,7,and 8 check you manual and it will tell you what the codes mean

 

also you're supposed to short that plug out w/ the car off ? did u?

 

Yes..since then plulled plug from A/T control unit and oped it up..looks brand new. I'm now thinking it the lock-up control solenoid. The cars shifts in and out of overdrive then may or may not flash. Tried jumper ECU again this time no codes but still having problem. Now which set of solenoids do I replace? Upper on lower? How difficult of a job or am I stabbing in the dark?