As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DEN FLIGHT NR 4015 DURING STARTUP, INITIALLY HAD AN APU FAULT. THAT MESSAGE WENT AWAY. STARTED APU UP AND AIRCRAFT WAS FILLED WITH A STRONG ODOR OF JET FUEL. REPLACED FUEL FILTER. PERFORMED OPERATIONAL TEST AND LEAK TEST OF APU IAW CRJ700 MM TASK 49-31-01-400-801-A01 STEP 2E. OPERATIONAL AND LEAK TEST GOOD. AIRCRAFT RETURNED TO SERVICE.