As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU "FAULT" LIGHT WHEN ATTEMPTED TO START APU AFTER LANDING. GROUNDED - YES. FOUND "NO FLAME SHUTDOWN" FAULT. ACCOMPLISHED B737-800 FIM 49-40 TASK 802. ACCOMPLISHED 2 SUCCESSFUL STARTS, NO FAULTS FOUND. REMOVED AND REPLACED APU EXCITER ASSY AND IGNITER PLUG, PER B737-800 AMM 49-41-31 AND AMM 49-41-51. OPS TEST NORMAL.