As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU AUTO SHUTDOWN TWICE DURING START ATTEMPTS. MAX RPM 27 PERCENT. BATTERY VOLTAGE DROPS TO 18V DURING START. REPLACED STARTER AND FLOW SENSING MODULE IAW AMM. APU STARTED NORMALLY SEVERAL TIMES, NORMAL APU BLEED PRESSURE DURING ENGINE STARTS AND ELECTRICAL LOADS.