Installed new p.c. with high perf. changes.Now throws U1000 code What,s-up with that.

 

U1000 - Class 2 Communication Malfunction (History) (Immature)
But i dont know exactly what that means.
Who tuned your PCM? Did you call him?

 

U1000 means that the PCM is noticing problems in the ClassII Databus. But, it has no clue whats wrong.

Double Check that your PCM connectors are seating properly, re-seat them while you're at it. As even a slight grounding issue can cause funny problems with the ClassII bus.

 

U1000 is a Communications DTC, may be set due to VIN not programmed into PCM

 

when I had jesse reprogam my pcm i had him remove lock-up from 3gear and moved 4gear lock-up to 55mph. because 2800 rpm 10" stall conv. was throwing code p0300. Probably because weight diff. in 10" from stock 11" conv.Now it doesnt throw p0300 code or u1000.now pcm pulls it out of lock up in 4th gear after about 1 mile or going
down a grade over 60 mph while in lock up. then i have to pull over, plug in my code clearer but the computer says there is no code, but then when i go back to over 55 mph it will go into lock up for a while.[QUOTE]