As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER STARTING THE APU, WHILE ON GROUND, POWER WITH EMERGENCY LIGHT SWITCH IN THE ARM POSITION, THE EMERGENCY LIGHTS CAME ON DURING THE AUTO TRANSFER FROM GROUND POWER TO APU POWER. MAINTENANCE TROUBLESHOT, R & R RELAY K135 AND PERFORMED CHECKS IAW THE AMM. THE ACFT WAS RELEASED FOR SERVICE.