TM 1-1520-238-T-4
4–109
4–28.
OIL BYP ENG 1 INDICATOR – IS LIGHTED
4–28
Tools:
Nomenclature
Part Number
Tool Kit, Electrical
SC518099CLA06
Repairer’s
Multimeter, Digital
AN/PSM-45
Personnel Required:
68F
Aircraft Electrician
References:
TM 1-1520-238-23
TM 55-2840-248-23
WARNING
Turn off power before detaching or
attaching wires and connectors. High
current 28 VDC or 115 VAC is present.
Failure to do so could result in death or
serious injury.
1. Detach P18 from pilot caution/warning panel.
Is OIL BYP ENG 1 indicator lighted?
YES
Replace pilot caution/warning
panel (TM 1-1520-238-23).
NO
Go to step 2.
2. Detach P21. Check for short between P18–17
and ground.
Does short exist?
YES
Repair shorted wire between
P448–B2 and P18–17,
P448–B2 and J21–46.
Go to paragraph 4–12.
NO
Go to step 3.
3. Detach P45. Check for short between P21–46
and ground.
Does short exist?
YES
(ABY) Repair shorted wire.
Go to paragraph 4–12.
(ABZ) Replace wire harness
(TM 1-1520-238-23).
NO
Refer to TM 55-2840-248-23 to
service engine 1 oil bypass filter.
END OF TASK
