TM 1–1520–238–T–3
Change 5
28–1
CHAPTER 28
DATA TRANSFER UNIT (DTU) (ADD)
MULTIPLEX READ CODES
FAILURE SYMPTOM INDEX
Symptom
Refer to paragraph
DATA TRANSFER UNIT NO–GO CPG COMPARTMENT MESSAGE
DISPLAYED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28–1
DTC BATTERY LOW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28–3
NO DTC MESSAGE REMAINS WITH DTC INSTALLED . . . . . . . . . . . . . . . . . . . 28–4
DTC READY DOES NOT APPEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28–5
DTC DOES NOT ZEROIZE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28–7
Personnel Required:
(2)
References:
TM 11–1520–238–23–1
TM 11–1520–238–23–2
Equipment Conditions:
Ref
Condition
TM 11–1520–238–23–2
DTU – MAINTENANCE
OPERATIONAL CHECK in
progress
TM 9–1230–476–20–2
MULTIPLEX SUBSYSTEM
– POWER UP completed
NOTE
All multiplex read code responses are read from right to
left.
Multiplex read codes must be used in conjunction with
applicable Maintenance Operational Check (MOC) in
progress.
MULTIPLEX READ CODE INTERPRETATIONS
28–1 SIGNAL NAME:
TERMINAL FLAG
MEMORY LOCATION: 002522
MEMORY DATA BIT(S):
19
(BINARY)
CONDITION:
(NONE)
SIGNAL FUNCTION:
Indicates terminal fault.
REMARKS: From DTU to FCC.
PASS:
If first digit on CDU is 4 or 0, go to paragraph 28–2.
FAIL: Location of fault: From DTU circuit breaker to DTR. Troubleshoot wiring to isolate fault
(TM 11–1520–238–23–2).
