What was found
MACH TRIM AND STAB TRIM CAUTION MESSAGES ON TAKEOFF. WOULD NOT RE-ENGAGE NORMALLY. SELECTED STAB TRIM DISCONNECT BUTTON. BOTH TRIMS ENGAGED AFTERWARDS. (FLIGHT #4312 FILED CLOSED) COMPLIED WITH FAULT ISOLATION PROCEDURE FOR STAB TRIM MACH TRIM CAUTION MESSAGES PER CRJ 200 FIM 27-40-00.FOUND LABEL 273 BIT 13 SET IN HSTCU DIAGNOSTIC DATA. PERFORMED GROUND MAINTENANCE TEST PER CRJ 200 AMM 27-41-00. VERIFIED FAULT IS NOT A LATCHED FAULT AND CLEARED UPON COMPLETION OF GROUND MAINTENANCE TEST. PERFORMED OPERATIONAL TEST OF STAB TRIM AND MACH TRIM ENGAGE SWITCH PER CRJ 200 AMM 27-41-25. OPERATIONAL TEST GOOD. PERFORMED WITH FLAPS IN TAKE OFF POSITION. DIAGNOSTIC DATA CONFIRMED NO FAULTS POST OPERATIONAL TEST. A/C OK FOR CONTINUED SERVICE.