As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER GROUND CREW HOOKED UP FOR TOW-IN APU SHUTDOWN INSTANTANEOUSLY. RESTARTED SUCCESSFULLY, BUT APU SHUTDOWN AGAIN AFTER TOW. PERFORMED APU BITE PROCEDURE PER B767 FIM 49-11 FAULT TREE 958, NO FAULTS FOUND AT THIS TIME. RESET BOX, OPS CHECK GOOD.