TM 1-1520-238-10 Change 2 2-83 Table 2-4. Pilot Caution/Warning Light Segments - continued Word Segment Illumination Parameter or Fault Color FUEL PSI ENG 2 RED No. 2 engine fuel pressure is less than 9 psi. ECS AMBER The overheat sensor has sensed a mixed air FAB temperature greater than 105 F (41 C). APU ON AMBER APU operation when APU N_G speed is above 95%. APU FAIL AMBER Indicates one of the following: APU thermocouple malfunction, overtemperature, overspeed, low APU oil pressure, or overcurrent. VIB GRBX AMBER Intermediate or tail rotor gearbox vibration level is excessive. FUEL XFR AMBER TRANS switch is in the TO FWD or TO AFT position and fuel transfer is not occurring. FUEL XFR Modified C/W panel GREEN TRANS selected, transfer is occurring. FUEL XFR Modified C/W panel AMBER TRANS selected, transfer is not occurring. X FEED Modified C/W panel GREEN CROSSFEED selected, fuel valves are correctly positioned. X FEED Modified C/W panel AMBER CROSSFEED selected, fuel valves are incorrectly positioned. ADS AMBER Failed system. BOOST PUMP ON AMBER Boost pump operation is on and providing 8 to 10 psi in fuel line to fuel filter. RDR JAM AMBER AN/ALQ-136 has failed, is off, or is in a warm-up cycle. IR JAM AMBER AN/ALQ-144 has failed, or is in warm-up/cool-down cycle. Table 2-5. CPG Caution/Warning Light Segments Word Segment Color Illumination Parameter or Fault IFF RED Mode 4 is not able to respond to interrogation. ENG 1 AMBER One or a combination of the following: engine oil pressure low, engine oil filter in bypass, engine chips, engine fuel filter in bypass, engine fuel pressure low, nose gearbox chips, nose gearbox oil pressure low, nose gearbox oil temperature high. MAIN XMSN 1 AMBER One or a combination of the following: transmission oil temperature high, oil pressure low. GUN AMBER Failed system.