What was found
AS THE THRUST LEVERS WERE ADVANCED FOR TAKEOFF, THE L REV UNLOCK CAUTION MESSAGE ILLUMINATED. THE FLIGHT CREW ELECTED TO ABORT THE TAKEOFF AND PULL OFF THE RUNWAY. THIS ACFT HAD A PREVIOUSLY DEFERRED LT THRUST REVERSER. DUE TO THE MEL REQUIREMENT TO REMOVE AND STOW THE CONNECTORS FROM THE POWER DRIVE UNIT, THE ILLUMINATION OF THE REV UNLOCK MESSAGE IS A COMMON OCCURRENCE. MX VERIFIED THAT THE THRUST REVERSER WAS PROPERLY DEFERRED INCLUDING THE INSTALLATION OF LOCKING PINS, AND THE ACFT WAS RELEASED FOR SERVICE.