Toyota Repair: CORROLA COMPUTER BOX- 160 GLE-1998, computer box, short circuit

Question
WHAT CAUSES A COMPUTER BOX AND CONTROL UNIT TO HAVE A SHORT CIRCUIT / BURN?  AFTER BUYING THESE TWO COMPONENTS DO THEY HAVE TO BE CODED OR INITIALISED?

Answer
A short circuit in the computer is normally caused by another component connected to the computer or shorted wiring, be sure to locate this problem before replacing the computer or the same thing may happen again, the replacement computer will work without doing anything else, just be sure the part numbers match exactly.