What was found
DURING APU SHUTDOWN FLAMES WERE COMING OUT OF EXHAUST, NO FIRE WARNING LIGHTS OR MSG OF ANY KIND. OPENED UP APU FIRE SWITCH AND DISCHARGED RT FIRE BOTTLE INTO APU, FIRE EXTINGUISHED. M2B- INSPECTED APU AND TAIL CONE AREA FOR DAMAGE NONE NOTED. PERFORMED ALERT SB GTCP-36-49-A7967 ON APU SHUT OFF SOLENOID VALVE, NO LEAK DETECTED. REMOVED AND REPLACED FUEL SHUT OFF SOLENOID VALVE WITH A OVERHAULED UNIT AND PERFORMED ALERT. GTCP36-49-A7867 AS WELL IAW MFG REP LOOSE IAW MFG GTCP36-150 MM CHAPTER 49-24-14. ALSO CHECKED FOR VOLTAGE AT FUEL SHUTOFF SOLENOID VALVE AT CONNECTOR AT BETWEEN PINS A+C NO VOLTAGE. ALSO REMOVED AND REPLACED ECU P/N 2118988-2 OFF S/N 102-00084 AND INSTALLED A MODIFIED ON + P/N2118988-2 S/N 68C0147 PER G-200 CMP CARD NR 494101. PERFORMED SEVERAL APU STARTS WITH NO DEFECTS NOTED. OPS CHECK SATISFACTORY.