As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FAULT LIGHT ILLUMINATED DURING APU START ATTEMPT. GROUNDED - YES. PER FIM 49-30 TASK 803. GVI OF COMPRESSOR INLET PLENUM IS GOOD, NO FOD FOUND. REMOVED AND REPLACED FUEL CONTROL UNIT. INSTALLATION TEST IS GOOD. NO LEAKS. APU BITE SHOWS NO FAULTS IAW AMM 49-31-11.