Failure of the TAT Sensor (PHC 2)

TASK 30-31-00-810-821-A
Failure of the TAT Sensor (PHC 2)

1. Possible Causes

SENSOR-TAT, 2 [11FP2]
PHC-2 [6DA2]
wiring from the PHC 2 (6DA2) to the TAT sensor 2 (11FP2)
wiring
ADIRU-2 [1FP2]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 30-31-00-710-001	Operational Test of the Probe Ice Protection
ASM 303102
AMM 30-31-34-000-002	Removal of the Probe Heat Computer (PHC)
AMM 30-31-34-400-002	Installation of the Probe Heat Computer (PHC)
AMM 34-11-18-000-001	Removal of the TAT Sensor
AMM 34-11-18-400-001	Installation of the TAT Sensor
AMM 34-12-34-000-001	Removal of the ADIRU
AMM 34-12-34-400-001	Installation of the ADIRU
ASM 341302

3. Fault Confirmation
Subtask 30-31-00-710-090-A

A. Test
(1) Do the operational test of the probe ice protection AMM 30-31-00-710-001.

4. Fault Isolation
Subtask 30-31-00-810-070-A

A. If the test gives the maintenance message TAT SENSOR 11FP2:

disconnect the connector from the TAT sensor 2 (11FP2) and do a check of the resistance between pin A/B and pin A/C.

(1) If the resistance is more than 31 ohms (open circuit) or less than 18 ohms (short circuit):
(a) Replace the SENSOR-TAT, 2 [11FP2] , AMM 34-11-18-000-001 and AMM 34-11-18-400-001.
(2) If the resistance is between 18 ohms and 31 ohms:
(a) Replace the PHC-2 [6DA2] , AMM 30-31-34-000-002 and AMM 30-31-34-400-002.
(b) If the fault continues:

do a check and repair the wiring from the PHC 2 (6DA2) to the TAT sensor 2 (11FP2) pin A/J to pin A/B ASM 303102.

(3) If the fault continues:
(a) Disconnect connector A from PHC 2 and remove ADIRU 2 AMM 34-12-34-000-001.
(b) Do a check of the probe signal wiring ASM 341302 between PHC 2 pin A/<A and ADIRU 2 pin AA/4F.
1 If there is no continuity:

Repair the wiring and
Install ADIRU 2 AMM 34-12-34-400-001.

2 If there is continuity:

Replace ADIRU-2 [1FP2] AMM 34-12-34-400-001.

Subtask 30-31-00-710-091-A

B. Do the operational test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:29:35 UTC