Failure of the TAT Sensor

TASK 30-31-00-810-810-A
Failure of the TAT Sensor

1. Possible Causes

SENSOR-TAT, 1 [11FP1]
PHC-1 [6DA1]
wiring from the PHC 1 (6DA1) to the TAT sensor 1 (11FP1)
wiring
ADIRU-1 [1FP1]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 30-31-00-710-001	Operational Test of the Probe Ice Protection
ASM 303101
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 30-31-00-710-068-A

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

4. Fault Isolation
Subtask 30-31-00-810-059-A

A. If the test gives the maintenance message TAT SENSOR 11FP1:

disconnect the connector from the TAT sensor 1 (11FP1) 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, 1 [11FP1] 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-1 [6DA1] 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 1 (6DA1) to the TAT sensor 1 (11FP1), pin A/J to pin A/B ASM 303101.

(3) If the fault continues:
(a) Disconnect connector A from PHC1 and remove ADIRU 1 and ADIRU 3 AMM 34-12-34-000-001.
(b) Do a check of the probe signal wiring ASM 341302 between:

PHC 1 pin A/<A and ADIRU 1 pin AA/4F
The first terminal block and ADIRU 3 pin AA/4F.

1 If there is no continuity:

Repair the wiring and
Install ADIRU 1 and ADIRU 3 AMM 34-12-34-400-001.

2 If there is continuity:

Install ADIRU 3 AMM 34-12-34-400-001.
Replace ADIRU-1 [1FP1] AMM 34-12-34-400-001.

Subtask 30-31-00-710-069-A

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

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