As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT NR 2403: DURING TAXI OUT, POWER PLANT MESSAGE ON ED. MAINTENANCE INTERROGATED EMU AND CDS. FOUND FAULT CODE 131B ON NR 1 ENGINE. PERFORMED FAULT ISOLATION IAW FIM 61-21-03-810-815. FOUND DIRTY PIN A PCU TRANSDUCER CONNECTOR P28. CLEANED CONNECTOR. FAULTS CLEARED. RAN NR 1 ENGINE. NO DEFECTS NOTED. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.