As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT THE APU AUTO SHUTDOWN WHEN BLEED AIR WAS SELECTED ON. THE MAINTENANCE TEAM DETERMINED THAT THE APU INLET TEMPERATURE SENSOR WAS DEFECTIVE. THE SENSOR WAS REMOVED P/N MS28034-1 S/N 168929 AND A NEW SENSOR WAS INSTALLED. FUNCTIONAL CHECKS WERE SATISFACTORY AND THE AIRCRAFT WAS RETURNED TO SERVICE.