LH Wing Loop B Inoperative

TASK 36-22-00-810-837-A
LH Wing Loop B Inoperative

1. Possible Causes

wiring
BMC-2 [1HA2]
CABLE ASSY [57HF]
OVHT SENS ELEMENT [63HF]
OVHT SENS ELEMENT [62HF]
OVHT SENS ELEMENT [61HF]
OVHT SENS ELEMENT [60HF]
OVERHEAT SENSING ELEM [59HF]
OVHT SENS ELEMENT [58HF]
OVHT SENS ELEMENT [78HF]
INTERCONNECTING CABLE [91HF]
SNSG ELEM-OVHT, L WING LOOP B [56HF]
SNSG ELEM-OVHT, L WING LOOP B [55HF]
SNSG ELEM-OVHT, L WING LOOP B [54HF]
SNSG ELEM-OVHT, L WING LOOP B [53HF]
OVHT SENS ELEMENT [33HF]
CABLE-CONNECTING, L WING LOOP B [52HF]
CABLE-CONNECTING, L WING LOOP B [51HF]
SNSG ELEM-OVHT, L WING LOOP B [50HF]
SNSG ELEM-OVHT, L WING LOOP B [49HF]
SNSG ELEM-OVHT, L WING LOOP B [83HF]
CABLE-CONNECTING, L WING LOOP B [77HF]

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
9240SI	1	CONTROLLER-LOOP

B. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 36-22-00-810-876-A	Leak Detection from the Loop B in the Left Wing
ESPM 204422
AMM 36-11-00-740-802	BITE Test of the Engine Bleed Air System (EBAS) (System Test)
AMM 36-11-34-000-001	Removal of the BMC
AMM 36-11-34-400-001	Installation of the BMC
AMM 36-22-00-100-803	Clean the Overheat Detection System (OHDS) Connectors and Apply the Electrical Insulating Compound
ASM 362201
AWM 362202
AMM 36-22-16-000-001	Removal of the Overheat Sensing Elements
AMM 36-22-16-000-002	Removal of the Cables
AMM 36-22-16-000-003	Removal of the Cables
AMM 36-22-16-000-004	Removal of the Overheat Sensing Elements
AMM 36-22-16-000-005	Removal of the Overheat Sensing Elements
AMM 36-22-16-000-006	Removal of the Overheat Sensing Elements
AMM 36-22-16-000-007	Removal of the Cables
AMM 36-22-16-400-001	Installation of the Overheat Sensing Elements
AMM 36-22-16-400-002	Installation of the Cables
AMM 36-22-16-400-003	Installation of the Cables
AMM 36-22-16-400-004	Installation of the Overheat Sensing Elements
AMM 36-22-16-400-005	Installation of the Overheat Sensing Elements
AMM 36-22-16-400-007	Installation of the Overheat Sensing Elements
AMM 36-22-16-400-008	Installation of the Cables

3. Fault Confirmation
Subtask 36-22-00-740-052-A ** ON A/C NOT FOR ALL

A. Test
(1) Do the BITE test of the EBAS AMM 36-11-00-740-802.

4. Fault Isolation
Subtask 36-22-00-810-094-B ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message L WING LOOP B INOP or L WING LOOP B OPEN:

NOTE: This procedure is applicable when there is a loss of the LH wing loop-B detection-signal or to the incorrect continuity of the loop.

Remove BMC-2 AMM 36-11-34-000-001.
On shelf 96VU, connect the 9240SI CONTROLLER-LOOP between BMC-2 pin AA/4G and AA/5G ASM 362201.
Do a check of the continuity resistance shown on the 9240SI CONTROLLER-LOOP:

(1) If the continuity resistance value is less than 16.5 Ohms:

On shelf 96VU, connect the 9240SI CONTROLLER-LOOP between connector BMC-2 pin AA/4G and the ground ASM 362201.
Do a check of the insulation resistance shown on the 9240SI CONTROLLER-LOOP.

(a) If the insulation resistance is more than 10 kOhms:

Go to Para. 4.B.

(b) If the insulation resistance is less than 10 kOhms:

Do the fault isolation steps (Ref. TSM TASK 36-22-00-810-876).

(2) If the continuity resistance value is more than 16.5 Ohms

Connect the 9240SI CONTROLLER-LOOP between connector 1968VC pin A/21 to connector 1901VC A/3 AWM 362202.

(a) If the continuity resistance value is more than 16.5 Ohms:

Do a visual inspection of the sensing elements and the connecting cables on LH wing loop B.

1 If a sensing element or a connecting cable is damaged:

Disconnect the 9240SI CONTROLLER-LOOP from connector 1968VC pin A/21 to connector 1901VC A/3.
Replace the defective sensing element or connecting cable
AMM 36-22-16-000-001 and AMM 36-22-16-400-001,
AMM 36-22-16-000-002 and AMM 36-22-16-400-002,
AMM 36-22-16-000-003 and AMM 36-22-16-400-003,
AMM 36-22-16-000-007 and AMM 36-22-16-400-008,
AMM 36-22-16-000-004 and AMM 36-22-16-400-004,
AMM 36-22-16-000-005 and AMM 36-22-16-400-005 and
AMM 36-22-16-000-006 and AMM 36-22-16-400-007.
Install BMC-2 AMM 36-11-34-400-001.

2 If no sensing element or connecting cable is damaged:

Go to Para. 4.B.

(b) If the continuity resistance value is less than 16.5 Ohms:

Connect the 9240SI CONTROLLER-LOOP between connector 1968VC pin A/21 and BMC-2 pin AA/4G AWM 362202.

1 If the continuity resistance value is more than 16.5 Ohms:

Disconnect the 9240SI CONTROLLER-LOOP from connector 1968VC pin A/21 and BMC-2 pin AA/4G.
Repair or replace the wiring ESPM 204422.
Install BMC-2 AMM 36-11-34-400-001.

2 If the continuity resistance value is less than 16.5 Ohms:

Connect the 9240SI CONTROLLER-LOOP between connector 1901VC pin A/3 and BMC-2 pin AA/5G AWM 362202.

a If the continuity resistance value is more than 16.5 Ohms:

Repair or replace the wiring ESPM 204422.
Install BMC-2 AMM 36-11-34-400-001.

b If the continuity resistance value is less than 16.5 Ohms:

Do the cleaning procedure AMM 36-22-00-100-803.
Do the BITE test of the EBAS AMM 36-11-00-740-802.
* If the fault continues:
** Replace BMC-2 [1HA2] AMM 36-11-34-000-001 and AMM 36-11-34-400-001.

Subtask 36-22-00-810-206-A ** ON A/C NOT FOR ALL

B. Dichotomy Procedure

NOTE: The purpose of this procedure is to find and isolate the elements that causes a high continuity resistance on loop-B of the LH wing.

(1) Do a check of the continuity resistance shown on the 9240SI CONTROLLER-LOOP:
(a) If the continuity resistance value is more than 16.5 Ohms:

Disconnect the connecting cable (57HF) of connector 1968VC pin A/21 and the connecting cable (77HF) of the connector 1901VC pin A/3 AMM 36-22-16-000-002. Disconnect one after the other all the sensing elements between the connection cables (57HF) and (77HF) AMM 36-22-16-000-001, AMM 36-22-16-000-003, AMM 36-22-16-000-007, AMM 36-22-16-000-004, AMM 36-22-16-000-005 and AMM 36-22-16-000-006.
Measure the continuity resistance with the 9240SI CONTROLLER-LOOP between the center pin on the two ends of each of the elements.
Do a check of the continuity resistance shown on the 9240SI CONTROLLER-LOOP:

1 If the continuity resistance value is more than 16.5 Ohms:

Disconnect the 9240SI CONTROLLER-LOOP.
Replace the defective elements:
CABLE ASSY [57HF] or
OVHT SENS ELEMENT [63HF] or
OVHT SENS ELEMENT [62HF] or
OVHT SENS ELEMENT [61HF] or
OVHT SENS ELEMENT [60HF] or
OVERHEAT SENSING ELEM [59HF] or
OVHT SENS ELEMENT [58HF] or
OVHT SENS ELEMENT [78HF] or
INTERCONNECTING CABLE [91HF] or
SNSG ELEM-OVHT, L WING LOOP B [56HF] or
SNSG ELEM-OVHT, L WING LOOP B [55HF] or
SNSG ELEM-OVHT, L WING LOOP B [54HF] or
SNSG ELEM-OVHT, L WING LOOP B [53HF] or
OVHT SENS ELEMENT [33HF] or
CABLE-CONNECTING, L WING LOOP B [52HF] or
CABLE-CONNECTING, L WING LOOP B [51HF] or
SNSG ELEM-OVHT, L WING LOOP B [50HF] or
SNSG ELEM-OVHT, L WING LOOP B [49HF] or
SNSG ELEM-OVHT, L WING LOOP B [83HF] or
CABLE-CONNECTING, L WING LOOP B [77HF]
AMM 36-22-16-000-001 and AMM 36-22-16-400-001,
AMM 36-22-16-000-002 and AMM 36-22-16-400-002,
AMM 36-22-16-000-003 and AMM 36-22-16-400-003,
AMM 36-22-16-000-007 and AMM 36-22-16-400-008,
AMM 36-22-16-000-004 and AMM 36-22-16-400-004,
AMM 36-22-16-000-005 and AMM 36-22-16-400-005 and
AMM 36-22-16-000-006 and AMM 36-22-16-400-007.
Install BMC-2 AMM 36-11-34-400-001.

2 If the continuity resistance value is less than 16.5 Ohms:

Disconnect the 9240SI CONTROLLER-LOOP.
Clean all the connections of the sensing elements and the connecting cables to remove contamination and decrease the resistance of the loop AMM 36-22-00-100-803 AWM 362202.
Connect again all the sensing elements or connecting cables disconnected AMM 36-22-16-400-001, AMM 36-22-16-400-002, AMM 36-22-16-400-003, AMM 36-22-16-400-008, AMM 36-22-16-400-004, AMM 36-22-16-400-005 and AMM 36-22-16-400-007.
Install BMC-2 AMM 36-11-34-400-001.

(b) If the continuity resistance value is less than 16.5 Ohms:

Disconnect the 9240SI CONTROLLER-LOOP.
Connect again all the sensing elements or connecting cables disconnected AMM 36-22-16-400-001, AMM 36-22-16-400-002, AMM 36-22-16-400-003, AMM 36-22-16-400-008, AMM 36-22-16-400-004, AMM 36-22-16-400-005 and AMM 36-22-16-400-007.
Replace BMC-2 [1HA2] AMM 36-11-34-000-001 and AMM 36-11-34-400-001.

[Rev.8 from Aug 2018] 2026.04.04 04:40:32 UTC