Pack 1/2 Inlet Pressure Sensor Fault

TASK 21-51-00-810-824-A
Pack 1/2 Inlet Pressure Sensor Fault

1. Possible Causes

SENSOR-PRESS, PACK 1 INLET [23HB1]
CONT-AIR COND SYSTEM 1 [47HH]
wiring
SENSOR-PRESS, PACK 2 INLET [24HB1]
CONT-AIR COND SYSTEM 2 [57HH]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 12-33-21-618-001	Pre-conditioning through the LP Ground Connection
AMM 21-51-13-000-001	Removal of the Pack-Inlet Pressure Sensor
AMM 21-51-13-400-001	Installation of the Pack-Inlet Pressure Sensor
ASM 216102
ASM 216104
AMM 21-61-34-000-002	Removal of the Air-Conditioning System Controller
AMM 21-61-34-400-002	Installation of the Air-Conditioning System Controller
AMM 31-32-00-860-002	Procedure to Get Access to the SYSTEM REPORT/TEST/AIR COND Page

3. Fault Confirmation
Subtask 21-51-00-710-085-C ** ON A/C NOT FOR ALL

A. Test
(1) Do a read out of the POST FLIGHT REPORT.
(2) Do the pre-conditioning of the air conditioning system with the APU AMM 12-33-21-618-001.
(3) On one MCDU, get the SYSTEM REPORT/TEST/AIR COND menu page AMM 31-32-00-860-002.
(4) On the MCDU push the line key adjacent to the TEMP CTL indication.

the CAB TEMP CONT menu page comes into view.

(5) On the CAB TEMP CONT menu page:

push the line key adjacent to the SYSTEM DATA indication.

(6) On the SYSTEM DATA menu page:

push the line key adjacent to the PRESS SENSORS indication.
the PRESS SENSORS SYSTEM DATA page comes into view.

(7) On the PRESS SENSORS SYSTEM DATA page:

compare the PACK 1 & 2 Bleed Pressure.

NOTE: PACK 1 & 2 Bleed Pressure must be almost equal.

compare the pack 1 Pack Inlet Pressure with the pack 1 Bleed Pressure.
compare the pack 2 Pack Inlet Pressure with the pack 2 Bleed Pressure.

NOTE: Bleed Pressure and Pack Inlet Pressure must be almost equal for each pack.

(8) After approximately 4 minutes, stop the pre-conditioning.

4. Fault Isolation
Subtask 21-51-00-810-098-D ** ON A/C NOT FOR ALL

A. If the POST FLIGHT REPORT gives the maintenance message,
P1 PR INL SENS(23HB1)/ P2 PRESS INL SENS(24HB1):
(1) If the test shows for PACK 1, a large difference between Pack Inlet Pressure and Bleed Pressure:

replace the SENSOR-PRESS, PACK 1 INLET [23HB1] AMM 21-51-13-000-001 and AMM 21-51-13-400-001.

(a) If the fault continues:

replace the CONT-AIR COND SYSTEM 1 [47HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.

(b) If the fault continues:

do a check and repair the wiring ASM 216104 from:
the PRESSURE SENSOR (23HB1) to the ACSC1 (47HH).

(2) If the test shows for PACK 2, a large difference between Pack Inlet Pressure and Bleed Pressure:

replace the SENSOR-PRESS, PACK 2 INLET [24HB1] AMM 21-51-13-000-001 and AMM 21-51-13-400-001.

(a) If the fault continues:

replace the CONT-AIR COND SYSTEM 2 [57HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.

(b) If the fault continues:

do a check and repair the wiring ASM 216102 from:
the PRESSURE SENSOR (24HB1) to the ACSC2 (57HH).

Subtask 21-51-00-720-059-A ** ON A/C NOT FOR ALL

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

[Rev.8 from Aug 2018] 2026.04.04 04:24:49 UTC