What was found
APU AUTO SHUTDOWN APPROX 30 MIN AFTER START, APU FAULT MESSAGE. TROUBLESHOT PER B767 FIM 49-11 TREE 909 GEN FILTER MSG ON ECU - APU INOP - ITEM PLACED ON DMI 148253 IAW MEL 49-11-01A, CAT C, DUE 19 JUN21. C/W AP-20109, PERFORMED AMM 49-20-00 GVI TASK NO FAULTS/BLOCKAGES. PERFORMED FIM 49-11 FT 987, NO FAULTS FOUND, WHILE PERFORMING FIM 49-11 FT 998, FOUND PIN 2 PUSHED AT P20 PLUG REF WDM 49-14-11 ALSO FOUND DIFFERENTIAL PRESSURE SWITCH TO BE FAULTY, PLUG P20 AND DIFFERENTIAL PRESSURE SWITCH ON ORDER, DMI REMAINS OPEN.</P><P>LP 1306177, ITEM M14: REMOVED AND REPLACED P20 PLUG AT GENERATOR OIL FILTER-DIFFERENTIAL SWITCH PER WDM 49-14-11, SWPM 20-74-20, AND AMM 49-27-15 FOR OPS CHECK.</P><P>LP 1306177, ITEM M15: REMOVED AND REPLACED GENERATOR OIL FILTER-DIFFERENTIAL SWITCH IAW B767-300 AMM 49-27-15 (<SPAN>S/N OFF: 90-50625-637, P/N OFF: 3876048-3</SPAN><SPAN>), OPS CHECK, NO FAULTS AT THIS TIME. THIS CLEARS DMI # 148253. MCC NOTIFIED. ALL PLACARDS REMOVED.</SPAN></P>)