As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU DUCT LEAK ILLUMINATED INFLIGHT WITH APU NOT OPERATING AND BLEEDS CLOSED. RETURNED TO SLC. CHECKED ALL DUCT LEAK SENSORS FOR APU BLEEDS IAW MM 36-20-00. RAN APU BLEEDS TO CHECK FOR LEAKS, NO LEAKS NOTED. DUCT LEAK SENSORS ALL OPS CHECK GOOD. NO FAULTS DETECTED. UNABLE TO DUPLICATE SQUAWK.