Active HPC Bleed Valve Pressure Signal Failure Channel A
TASK 75-32-00-810-850-A
Active HPC Bleed Valve Pressure Signal Failure Channel A
1. Possible Causes
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Fault Confirmation
Subtask 75-32-00-710-105-A ** ON A/C NOT FOR ALL
Subtask 75-32-00-860-068-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:37:23 UTC
Active HPC Bleed Valve Pressure Signal Failure Channel A
1. Possible Causes
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | MULTIMETER - STANDARD |
| No specific | 1 | PLIERS - JAWED, SOFT |
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 71-00-00-810-834-A | General Troubleshooting Guidelines for Additional Troubleshooting Information |
| TSM TASK 71-00-00-810-835-A | Component and Harness Intermittent Troubleshooting Procedure for Guidance Troubleshooting Intermittent Faults |
| AMM 70-70-00-910-803 | SPOP 6 - Cleaning of the Contact Points and Wiring Harnesses |
| AMM 73-21-00-710-806 | Test No.7 - EEC Operation Test (Self Test) |
| AMM 73-21-01-000-801 | Removal of the Electronic Engine Control (EEC) |
| AMM 73-21-01-400-801 | Installation of the Electronic Engine Control (EEC) |
| AMM 73-21-63-000-802 | Removal of the Electronic Engine Control (EEC) Wiring Harness (W03) |
| AMM 73-21-63-400-802 | Installation of the Electronic Engine Control (EEC) Wiring Harness (W03) |
| AMM 73-21-64-000-802 | Removal of the Electronic Engine Control (EEC) Wiring Harness (W04) |
| AMM 73-21-64-400-802 | Installation of the Electronic Engine Control (EEC) Wiring Harness (W04) |
| AMM 75-32-21-000-801 | Removal of the HPC Bleed Valve Air Pressure Sensor (Passive) |
| AMM 75-32-21-400-801 | Installation of the HPC Bleed Valve Air Pressure Sensor (Passive) |
| AMM 78-36-00-010-802 | Opening of the Thrust Reverser Cowl-Doors |
| AMM 78-36-00-410-802 | Closing of the Thrust Reverser Cowl-Doors |
Subtask 75-32-00-710-105-A ** ON A/C NOT FOR ALL
A. Do the EEC system interactive test to confirm this fault. Refer to FADEC self test AMM 73-21-00-710-806.
(a) If no problems are found, return the engine to service. Monitor the engine for reoccurring maintenance message.
(2) If the maintenance message comes back (hard fault), go to the Para. Fault Isolation.
4. Fault IsolationNOTE: The Electronic Engine Control (EEC) has detected that the active High Pressure Compressor (HPC) bleed valve air pressure sensor circuit is out of range or rate in channel A. The active HPC bleed valve air pressure sensor is located at the 2 o'clock position on the compressor intermediate case fire seal bulkhead.
(1) If the maintenance message does not come back, examine the harnesses and electrical connectors as described in the component and harness intermittent fault isolation procedure (Ref. TSM TASK 71-00-00-810-835). - Refer to the general troubleshooting guidelines for additional troubleshooting information (Ref. TSM TASK 71-00-00-810-834).
- Refer to the component and harness intermittent troubleshooting procedure for guidance troubleshooting intermittent faults (Ref. TSM TASK 71-00-00-810-835).
(a) If no problems are found, return the engine to service. Monitor the engine for reoccurring maintenance message.
(2) If the maintenance message comes back (hard fault), go to the Para. Fault Isolation.
WARNING:
BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.
WARNING:
REFER TO THE MSDS FOR ALL MATERIAL USED AND THE MANUFACTURER'S SAFETY INSTRUCTIONS FOR ALL EQUIPMENT USED. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.
CAUTION:
MAKE SURE YOU REMOVE ELECTRICAL POWER FROM THE EEC BEFORE YOU REMOVE THE ELECTRICAL CONNECTORS. IF YOU DO NOT OBEY THIS INSTRUCTION, DAMAGE TO THE EEC CAN OCCUR.
Subtask 75-32-00-810-107-A ** ON A/C NOT FOR ALL A. If there is confirmation of the fault:
(1) Open the thrust reverser cowl-doors AMM 78-36-00-010-802.
(2) Examine the W04 (4088KS) and W03 (4087KS) harnesses, connector P13 (4000KS-P13) - EEC (4000KS), interconnect J106 (4100VC)/P106 (4100VC-A) and connector P56 (4184KS-P56) - Active HPC bleed valve air pressure sensor (4184KS), for problems which are possible between the EEC (4000KS) and the active HPC bleed valve air pressure sensor (4184KS).
(a) Inspect for harness damage.
(b) Inspect for loose or damaged connectors.
1 Replace W04 HARNESS(4088KS) AMM 73-21-64-000-802 and AMM 73-21-64-400-802, or
2 Replace W03 HARNESS(4087KS) AMM 73-21-63-000-802 and AMM 73-21-63-400-802.
3 Do the test given in Para. 3.
(3) If no problems are found with the harnesses or the fault continues, use a PLIERS - JAWED, SOFT to disconnect the electrical connector P13 (4000KS-P13) from the EEC (4000KS), interconnect J106 (4100VC)/P106 (4100VC-A) and connector P56 (4184KS-P56) from the active HPC bleed valve air pressure sensor (4184KS).
(a) Examine the pins and sockets (contacts) for alignment and damage. Look for contacts pushed rearward into the connector face. Replace parts as necessary.
(b) Clean the contacts with contact cleaner and clean cloth per SPOP 6. Blow dry with air (at less than 30 psi) across the connector face AMM 70-70-00-910-803.
(c) Reconnect the electrical connector P13 (4000KS-P13) to the EEC (4000KS), interconnect J106 (4100VC)/P106 (4100VC-A) and connector P56 (4184KS-P56) to the active HPC bleed valve air pressure sensor (4184KS).
(d) Do the test given in Para. 3.
(4) If the fault continues:
(a) Replace SENSOR-AIR PRESSURE, HPC BLEED VALVE [4184KS] AMM 75-32-21-000-801 and AMM 75-32-21-400-801.
(b) Do the test given in Para. 3.
(5) If the fault continues:
(a) Disconnect the electrical connector P13 (4000KS-P13) from the EEC (4000KS), interconnect J106 (4100VC)/P106 (4100VC-A) and connector P56 (4184KS-P56) from the active HPC bleed valve air pressure sensor (4184KS). Use a MULTIMETER - STANDARD to test the active HPC bleed valve air pressure sensor (4184KS) circuits in the harnesses. Refer to Table 1. Look for:
1 Wire-to-wire shorts
2 Shorts to ground
3 Continuity (less than 5 ohms resistance).
(b) If a problem is found with the harnesses or connectors:
1 Replace W04 HARNESS [4088KS] AMM 73-21-64-000-802 and AMM 73-21-64-400-802, or
2 Replace W03 HARNESS [4087KS] AMM 73-21-63-000-802 and AMM 73-21-63-400-802.
3 Do the test given in Para. 3.
(6) If no problems are found with the harnesses or the fault continues:
(a) Replace [4000KS] AMM 73-21-01-000-801 and AMM 73-21-01-400-801.
(b) Do the test given in Para. 3.
5. Close-up(1) Open the thrust reverser cowl-doors AMM 78-36-00-010-802.
(2) Examine the W04 (4088KS) and W03 (4087KS) harnesses, connector P13 (4000KS-P13) - EEC (4000KS), interconnect J106 (4100VC)/P106 (4100VC-A) and connector P56 (4184KS-P56) - Active HPC bleed valve air pressure sensor (4184KS), for problems which are possible between the EEC (4000KS) and the active HPC bleed valve air pressure sensor (4184KS).
(a) Inspect for harness damage.
(b) Inspect for loose or damaged connectors.
NOTE: Loose connectors must be disconnected and examined for further wear or damage.
(c) If a problem is found with the harnesses or connectors: 1 Replace W04 HARNESS(4088KS) AMM 73-21-64-000-802 and AMM 73-21-64-400-802, or
2 Replace W03 HARNESS(4087KS) AMM 73-21-63-000-802 and AMM 73-21-63-400-802.
3 Do the test given in Para. 3.
(3) If no problems are found with the harnesses or the fault continues, use a PLIERS - JAWED, SOFT to disconnect the electrical connector P13 (4000KS-P13) from the EEC (4000KS), interconnect J106 (4100VC)/P106 (4100VC-A) and connector P56 (4184KS-P56) from the active HPC bleed valve air pressure sensor (4184KS).
(a) Examine the pins and sockets (contacts) for alignment and damage. Look for contacts pushed rearward into the connector face. Replace parts as necessary.
(b) Clean the contacts with contact cleaner and clean cloth per SPOP 6. Blow dry with air (at less than 30 psi) across the connector face AMM 70-70-00-910-803.
(c) Reconnect the electrical connector P13 (4000KS-P13) to the EEC (4000KS), interconnect J106 (4100VC)/P106 (4100VC-A) and connector P56 (4184KS-P56) to the active HPC bleed valve air pressure sensor (4184KS).
(d) Do the test given in Para. 3.
(4) If the fault continues:
(a) Replace SENSOR-AIR PRESSURE, HPC BLEED VALVE [4184KS] AMM 75-32-21-000-801 and AMM 75-32-21-400-801.
(b) Do the test given in Para. 3.
(5) If the fault continues:
(a) Disconnect the electrical connector P13 (4000KS-P13) from the EEC (4000KS), interconnect J106 (4100VC)/P106 (4100VC-A) and connector P56 (4184KS-P56) from the active HPC bleed valve air pressure sensor (4184KS). Use a MULTIMETER - STANDARD to test the active HPC bleed valve air pressure sensor (4184KS) circuits in the harnesses. Refer to Table 1. Look for:
1 Wire-to-wire shorts
2 Shorts to ground
3 Continuity (less than 5 ohms resistance).
NOTE: A short to ground is found when the resistance is less than 100 000 (100K) ohms.
Table 1: Active HPC Bleed Valve Air Pressure Sensor Channel A Connector Contacts | W04 (4088KS) Harness P13 (4000KS-P13) EEC (4000KS) Connector Contacts | W04 (4088KS) Harness J106 (4100VC) Connector Contacts | W03 (4087KS) Harness P106 (4100VC-A) Connector Contacts | W03 (4087KS) Harness P56 (4184KS-P56) Active HPC Bleed Valve Air Pressure Sensor (4184KS) Connector Contacts |
|---|---|---|---|
| AA | 32 | 32 | 12 |
| H | 55 | 55 | 4 |
| z | 56 | 56 | 3 |
| h | 57 | 57 | 11 |
1 Replace W04 HARNESS [4088KS] AMM 73-21-64-000-802 and AMM 73-21-64-400-802, or
2 Replace W03 HARNESS [4087KS] AMM 73-21-63-000-802 and AMM 73-21-63-400-802.
3 Do the test given in Para. 3.
(6) If no problems are found with the harnesses or the fault continues:
(a) Replace
(b) Do the test given in Para. 3.
Subtask 75-32-00-860-068-A ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(a) Close the thrust reverser cowl-doors AMM 78-36-00-410-802.
(1) Make sure that the work area is clean and clear of tools and other items.
(a) Close the thrust reverser cowl-doors AMM 78-36-00-410-802.
W03/W04 Wiring Harness Interconnect