TM 1–1520–238–T–3
Change 5
22–1
CHAPTER 22
POWER PLANTS MULTIPLEX READ CODES
FAILURE SYMPTOM INDEX
Symptom
Refer to paragraph
ENGINE NO. 1 TORQUE INDICATION IS LOWER THAN ENGINE NO. 2
TORQUE INDICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22–1
ENGINE NO. 2 TORQUE INDICATION IS LOWER THAN ENGINE NO. 1
TORQUE INDICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22–2
Personnel Required:
(2)
References:
TM 1–1520–238–T–4
Equipment Conditions:
Ref
Condition
TM 1–1520–238–T–4
TORQUE SHARING
SYSTEM –
MAINTENANCE
OPERATIONAL CHECK in
progress
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 codes are observed on the HOD (ADC) or
CDU (ADD).
MULTIPLEX READ CODE INTERPRETATIONS
22–1 SIGNAL NAME:
ENG 1 TORQUE
MEMORY LOCATION: 002120
MEMORY DATA BIT(S):
4–19 (ACY) 4–15 (ACZ)
(SCALAR)
CONDITION:
Monitor HOD while turning up engines; memory location response digits should
increase and display will limit at 120.
SIGNAL FUNCTION:
Monitors engine 1 torque.
REMARKS: From engine 1 torque sensor to engine 1 electronic control unit (ECU) or digital electronic
control unit (DECU) through digital automatic stabilization equipment computer (DASEC)
to fire control computer (FCC).
PASS:
If CONDITION is met, go to Chapter 14, paragraph 14–135.
FAIL: Location of fault: engine 1 torque sensor, wiring from engine 1 torque sensor to ECU or DECU,
ECU or DECU, wiring from ECU or DECU to DASEC, DASEC. Troubleshoot wiring to isolate
fault (TM 1–1520–238–T–4).
