Erroneous TAT Value Read on the Lower ECAM DU on Ground

TASK 34-11-00-810-896-A
Erroneous TAT Value Read on the Lower ECAM DU on Ground

1. Possible Causes

PHC-2 [6DA2]
wiring between the PHC2 and the ADIRU2
wiring between the ADIRU1 and the first terminal block
wiring between the ADIRU3 and the first terminal block
PHC-1 [6DA1]
wiring between the PHC1 and the first terminal block
wiring between the PHC1 and the ADIRU1

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
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)
ASM 341302

3. Fault Confirmation
Subtask 34-11-00-700-057-A

A. Test
Not applicable, the fault is evident.

4. Fault Isolation
Subtask 34-11-00-810-215-A ** ON A/C NOT FOR ALL

A. If the fault symptom is identified by the crew observation, ADIRS - TAT reading error of 11 deg. C on the lower ECAM DU:
(1) With the AIR DATA selector switch (15FP) and the ECAM/ND XFR selector switch (19WT) in the NORM positions:

replace the PHC-2 [6DA2] AMM 30-31-34-000-002 and AMM 30-31-34-400-002.

(a) If the fault continues:

do a check and repair the wiring between the PHC2 and the ADIRU2 for pin AA/4F of the ADIRU2 ASM 341302.

(2) With the AIR DATA selector switch (15FP) in the NORM position and the ECAM/ND XFR selector switch (19WT) in the F/O position:

do a check and repair the wiring between the ADIRU1 and the first terminal block for pin AA/4F of the ADIRU1 ASM 341302.

(3) With the AIR DATA selector switch (15FP) in the CAPT/3 position and the ECAM/ND XFR selector switch (19WT) in the F/O position:

do a check and repair the wiring between the ADIRU3 and the first terminal block for pin AA/4F of the ADIRU3 ASM 341302.

(4) With the AIR DATA selector switch (15FP) in the NORM and then in the CAPT/3 positions and the ECAM/ND XFR selector switch (19WT) in the F/O position:

replace the PHC-1 [6DA1] AMM 30-31-34-000-002 and AMM 30-31-34-400-002.

(a) If the fault continues:

do a check and repair the wiring between the PHC1 and the first terminal block for pin AA/<A of the PHC1 ASM 341302.

Subtask 34-11-00-810-215-B ** ON A/C NOT FOR ALL

replace the PHC-1 [6DA1] AMM 30-31-34-000-002 and AMM 30-31-34-400-002.

(a) If the fault continues:

do a check and repair the wiring between the PHC1 and the ADIRU1 for pin AA/4F of the ADIRU1 ASM 341302.

(2) With the AIR DATA selector switch (15FP) in the NORM position and the ECAM/ND XFR selector switch (19WT) in the CAPT position:

do a check and repair the wiring between the ADIRU1 and the first terminal block for pin AA/4F of the ADIRU1 ASM 341302.

(3) With the AIR DATA selector switch (15FP) in the CAPT/3 position and the ECAM/ND XFR selector switch (19WT) in the CAPT position:

do a check and repair the wiring between the ADIRU3 and the first terminal block for pin AA/4F of the ADIRU3 ASM 341302.

(4) With the AIR DATA selector switch (15FP) in the NORM and then in the CAPT/3 positions and the ECAM/ND XFR selector switch (19WT) in the CAPT position:

replace the PHC-1 [6DA1] AMM 30-31-34-000-002 and AMM 30-31-34-400-002.

(a) If the fault continues:

do a check and repair the wiring between the PHC1 and the first terminal block for pin AA/<A of the PHC1 ASM 341302.

[Rev.8 from Aug 2018] 2026.04.04 04:32:19 UTC