REVVING OF ENGINE TO POINT OF SCREECHING TIRES. SOMETIMES FEELING OF BEING IN NEUTRAL FOR A SECOND THEN CLUNK IN TRANNY/REAR END? ACTS AS ENGAGEMENT OF CRUISE CONTROL INCREASING SPEED, NOT ABLE TO DISENGAGE BY HITTING BRAKE. COMPUTER DID NOT SHOW ANYTHING. NEXT TIME PUTTER "LOCKED OUT" TECH'S. PUTER REPLACED. WORKED GOOD FOR TWO WEEKS. ENGINE REVVED, HIT PATCH OF ICE, TOTALED OUT Z-71. THANK GOD, NO INJURIES. FIGHTING IT FOR APPX 16000 MILES. 72000 TO 88000. *TR