TM 1–1520–238–T–3
4–2
MULTIPLEX READ CODE INTERPRETATIONS
4–1 SIGNAL NAME: CPG ANTI–ICE SW
MEMORY LOCATION: 000437
MEMORY DATA BIT(S): 19 (BINARY)
CONDITION: CPG ANTI–ICE SW to GND
SIGNAL FUNCTION: Monitors position of copilot/gunner (CPG) AUX/ANTI ICE panel TADS/PNVS
switch.
REMARKS: From CPG AUX/ANTI ICE panel TADS/PNVS switch through CPG multiplex remote
terminal unit (MRTU) Type III to fire control computer (FCC). Enables or disables anti–ice
functions for target acquisition designation sight (TADS)/pilot night vision sensor (PNVS).
PASS: If first digit on heads out display (HOD) is 1, 3, 5, or 7, go to paragraph 4–2.
FAIL: Location of fault: CPG AUX/ANTI ICE panel TADS/PNVS switch, wiring from CPG AUX/ANTI
ICE panel TADS/PNVS switch to CPG MRTU Type III, CPG MRTU Type III. Troubleshoot
wiring to isolate fault (TM 1–1520–238–T–8).
4–2 SIGNAL NAME: PLT ANTI–ICE SW
MEMORY LOCATION: 001117
MEMORY DATA BIT(S): 16 (BINARY)
CONDITION: Pilot ANTI–ICE PANEL SW to GND
SIGNAL FUNCTION: Monitors position of pilot ANTI ICE panel TADS/PNVS switch.
REMARKS: From pilot ANTI ICE panel TADS/PNVS switch through left–hand (LH) forward avionics
bay (FAB) MRTU Type I to FCC. Enables or disables anti–ice functions for TADS/PNVS.
PASS: If second digit on HOD is 1, 3, 5, or 7, go to failure symptom index and next failure symptom
paragraph.
FAIL: Location of fault: pilot ANTI ICE panel TADS/PNVS switch, wiring from pilot ANTI ICE panel
TADS/PNVS switch to LH FAB MRTU Type I, LH FAB MRTU Type I. Troubleshoot wiring to
isolate fault (TM 1–1520–238–T–8).
4–3 SIGNAL NAME: WICE POWER STATUS
MEMORY LOCATION: 001117
MEMORY DATA BIT(S): 15 (BINARY)
CONDITION: (None)
SIGNAL FUNCTION: Monitors windshield de–ice power status.
REMARKS: From pilot ANTI ICE panel CANOPY HTR switch through LH FAB MRTU Type I to FCC.
Enables or disables windshield de–icing.
PASS: If second digit on HOD is 2, 3, 6, or 7, go to paragraph 4–4.
FAIL: Location of fault: pilot ANTI ICE panel CANOPY HTR switch, wiring from pilot ANTI ICE panel
CANOPY HTR switch to LH FAB MRTU Type I, LH FAB MRTU Type I. Troubleshoot wiring to
isolate fault (TM 1–1520–238–T–8).
