Engine 2 Pylon Loop B Inoperative
TASK 36-22-00-810-835-A
Engine 2 Pylon Loop B Inoperative
1. Possible Causes
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Fault Confirmation
Subtask 36-22-00-740-057-A ** ON A/C NOT FOR ALL 4. Fault Isolation
Subtask 36-22-00-810-103-B ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:34:06 UTC
Engine 2 Pylon Loop B Inoperative
1. Possible Causes
- wiring
- BMC-2 [1HA2]
- SENSING ELEMENT-OVHT, R PYLON LOOP B [101HF2]
- CABLE-CONNECTING, R PYLON LOOP B [104HF2]
- CABLE-CONNECTING, R PYLON LOOP B [102HF2]
- SENSING ELEMENT-OVHT, R PYLON LOOP B [106HF2]
- CABLE-CONNECTING, R PYLON LOOP B [103HF2]
- CABLE-CONNECTING, R PYLON LOOP B [105HF2]
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| 9240SI | 1 | CONTROLLER-LOOP |
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 36-22-00-810-885-A | Leak Detection of the Engine 2 Pylon Loop B |
| 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 36-22-15-000-802 | Removal of the Pylon Overheat Sensing-Elements |
| AMM 36-22-15-000-803 | Removal of the Pylon Overheat Sensing-Elements |
| AMM 36-22-15-400-802 | Installation of the Pylon Overheat Sensing-Elements |
| AMM 36-22-15-400-803 | Installation of the Pylon Overheat Sensing-Elements |
Subtask 36-22-00-740-057-A ** ON A/C NOT FOR ALL 4. Fault Isolation
Subtask 36-22-00-810-103-B ** ON A/C NOT FOR ALL
A. If the test gives the maintenance message ENG2 PYLON LOOP B INOP or ENG2 PYLON LOOP B OPEN:
Subtask 36-22-00-810-204-A ** ON A/C NOT FOR ALL NOTE: This procedure is applicable when there is a loss of the engine-2 pylon 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/4D and AA/5D ASM 362201.
- Do a check of the continuity resistance shown on the 9240SI CONTROLLER-LOOP:
- On shelf 96VU, connect the 9240SI CONTROLLER-LOOP between connector BMC-2 pin AA/4D and the ground ASM 362201.
- Do a check of the insulation resistance shown on the 9240SI CONTROLLER-LOOP.
- Go to Para. 4.B.
- Do the fault isolation steps (Ref. TSM TASK 36-22-00-810-885).
- Connect the 9240SI CONTROLLER-LOOP between connector 410VC pin A/14 to A/13 AWM 362202.
- Do a visual inspection of the sensing elements and the connecting cables on engine 2 pylon loop B.
- Disconnect the 9240SI CONTROLLER-LOOP from connector 410VC pin A/14 to A/13.
- Replace the defective sensing element or connecting cable AMM 36-22-15-000-802 and AMM 36-22-15-400-802, AMM 36-22-15-000-803 and AMM 36-22-15-400-803.
- Install BMC-2 AMM 36-11-34-400-001.
- Go to Para. 4.B.
- Connect the 9240SI CONTROLLER-LOOP between connector 410VC pin A/14 and BMC-2 pin AA/4D AWM 362202.
- Disconnect the 9240SI CONTROLLER-LOOP from connector 410VC pin A/14 and BMC-2 pin AA/4D.
- Repair or replace the wiring ESPM 204422.
- Install BMC-2 AMM 36-11-34-400-001.
- Connect the 9240SI CONTROLLER-LOOP between connector 410VC pin A/13 and BMC-2 pin AA/5D AWM 362202.
- Repair or replace the wiring ESPM 204422.
- Install BMC-2 AMM 36-11-34-400-001.
- 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.
B. Dichotomy Procedure
(2) Do a check of the continuity resistance shown on the 9240SI CONTROLLER-LOOP:
(a) If the continuity resistance value is more than 8 Ohms:
NOTE: The purpose of this procedure is to find and isolate the element that causes a high continuity resistance on loop-B of the engine-2 pylon.
(1) Connect the 9240SI CONTROLLER-LOOP between connector 410VC pin A/14 to terminal block 450VT2 pin 2/A AWM 362202. (2) Do a check of the continuity resistance shown on the 9240SI CONTROLLER-LOOP:
(a) If the continuity resistance value is more than 8 Ohms:
- Disconnect the sensing element (101HF2) from connecting cables (102HF2) and (104HF2) AMM 36-22-15-000-803.
- Measure the continuity resistance with the 9240SI CONTROLLER-LOOP between the center pin on the two ends of each of the sensing element.
- Do a check of the continuity resistance shown on the 9240SI CONTROLLER-LOOP:
- Disconnect the 9240SI CONTROLLER-LOOP.
- Replace the defective SENSING ELEMENT-OVHT, R PYLON LOOP B [101HF2] or CABLE-CONNECTING, R PYLON LOOP B [104HF2] or CABLE-CONNECTING, R PYLON LOOP B [102HF2] AMM 36-22-15-000-803 and AMM 36-22-15-400-803.
- Install BMC-2 AMM 36-11-34-400-001.
- Disconnect the 9240SI CONTROLLER-LOOP.
- Clean all the connections of sensing element (101HF2) and connecting cables (102HF2) and (104HF2) to remove contamination and decrease the resistance of the loop AMM 36-22-00-100-803 AWM 362202.
- Install the sensing element (101HF2) AMM 36-22-15-400-803.
- Install BMC-2 AMM 36-11-34-400-001.
- Connect the 9240SI CONTROLLER-LOOP between connector 410VC pin A/13 to terminal block 450VT2 pin 2/B AWM 362202.
- Do a check of the continuity resistance shown on the 9240SI CONTROLLER-LOOP:
- Disconnect the sensing element (106HF2) from connecting cables (103HF2) and (105HF2) AMM 36-22-15-000-802.
- Measure the continuity resistance with the 9240SI CONTROLLER-LOOP between the center pin on the two ends of each of the sensing elements.
- Do a check of the continuity resistance shown on the 9240SI CONTROLLER-LOOP:
- Disconnect the 9240SI CONTROLLER-LOOP.
- Replace the defective SENSING ELEMENT-OVHT, R PYLON LOOP B [106HF2] or CABLE-CONNECTING, R PYLON LOOP B [103HF2] or CABLE-CONNECTING, R PYLON LOOP B [105HF2] AMM 36-22-15-000-802 and AMM 36-22-15-400-802.
- Install BMC-2 AMM 36-11-34-400-001.
- Disconnect the 9240SI CONTROLLER-LOOP.
- Clean all the connections of sensing element (106HF2) and connecting cables (103HF2) and (105HF2) to remove contamination and decrease the resistance of the loop AMM 36-22-00-100-803 AWM 362202.
- Install the sensing element (106HF2) AMM 36-22-15-400-802.
- Install BMC-2 AMM 36-11-34-400-001.
- Disconnect the 9240SI CONTROLLER-LOOP.
- Connect again all the sensing elements or connecting cables disconnected AMM 36-22-15-400-802.
- Replace BMC-2 [1HA2] AMM 36-11-34-000-001 and AMM 36-11-34-400-001.