PB Sensor Dual in Range High Failure
TASK 73-21-00-810-911-A
PB Sensor Dual in Range High Failure
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
3. Fault Confirmation
Subtask 73-21-00-710-163-A ** ON A/C NOT FOR ALL
Subtask 73-21-00-860-100-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:36:43 UTC
PB Sensor Dual in Range High Failure
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
| 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 73-21-00-200-806 | Electronic Engine Control (EEC) Sensing System Check |
| AMM 73-21-00-710-807 | Test No.6 - EEC Operation Test (Idle 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 73-21-23-000-801 | Removal of the Burner Pressure Sensor |
| AMM 73-21-23-400-801 | Installation of the Burner Pressure Sensor |
| 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 73-21-00-710-163-A ** ON A/C NOT FOR ALL
A. Not Applicable
4. Fault IsolationNOTE: The Electronic Engine Control (EEC) has detected the Burner Pressure (PB) sense line from the diffuser case to the Burner Pressure (PB) sensor is clogged. The PB sensor is located on the aft side of the compressor intermediate case bulkhead at the 10 o'clock position. The PB sensor is wired to channel A and channel B of the EEC.
- 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 fault (Ref. TSM TASK 71-00-00-810-835).
NOTE: Inspection of the PB sensing system is recommended before any operational checks are performed for this fault. Loose fittings, cracks or contamination in the line may not allow the fault to reproduce on the ground in the same manner as it occurred during flight operation.
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 73-21-00-810-180-A ** ON A/C NOT FOR ALL A. Do the steps that follow:
(1) Open the thrust reverser cowl-doors AMM 78-36-00-010-802.
(2) Visually inspect the PB sense line and PB sensor (4085KS) AMM 73-21-00-200-806.
(a) Visually inspect the PB sense line from diffuser case to the PB sensor (4085KS) for damage, cracks, or loose connections.
(b) Repair any problems found.
(c) Do the repair confirmation. Refer to the Para. 4.B.
(3) If no problems are found, blow out the PB sensor (4085KS) fitting with low pressure compressed air or nitrogen AMM 73-21-00-200-806.
(b) Do the repair confirmation. Refer to the Para. 4.B.
(4) If the fault continues:
(a) Replace SENSOR - P3 [4085KS] AMM 73-21-23-000-801 and AMM 73-21-23-400-801.
(b) Do the repair confirmation. Refer to the Para. 4.B.
(5) If the fault continues:
(a) Replace [4000KS] AMM 73-21-01-000-801 and AMM 73-21-01-400-801.
(b) Do the repair confirmation. Refer to the Para. 4.B.
Subtask 73-21-00-710-164-A ** ON A/C NOT FOR ALL (1) Open the thrust reverser cowl-doors AMM 78-36-00-010-802.
(2) Visually inspect the PB sense line and PB sensor (4085KS) AMM 73-21-00-200-806.
(a) Visually inspect the PB sense line from diffuser case to the PB sensor (4085KS) for damage, cracks, or loose connections.
(b) Repair any problems found.
(c) Do the repair confirmation. Refer to the Para. 4.B.
(3) If no problems are found, blow out the PB sensor (4085KS) fitting with low pressure compressed air or nitrogen AMM 73-21-00-200-806.
NOTE: Do not blow compressed air or nitrogen directly into the PB sensor (4085KS), the sensor may be damaged.
(a) Repair any problems found. (b) Do the repair confirmation. Refer to the Para. 4.B.
(4) If the fault continues:
(a) Replace SENSOR - P3 [4085KS] AMM 73-21-23-000-801 and AMM 73-21-23-400-801.
(b) Do the repair confirmation. Refer to the Para. 4.B.
(5) If the fault continues:
(a) Replace
(b) Do the repair confirmation. Refer to the Para. 4.B.
B. Repair Confirmation
(1) Do an engine run to idle to confirm repair of this fault. Refer to the EEC operation test (Idle test) - Test N°6 AMM 73-21-00-710-807.
5. Close-up(1) Do an engine run to idle to confirm repair of this fault. Refer to the EEC operation test (Idle test) - Test N°6 AMM 73-21-00-710-807.
Subtask 73-21-00-860-100-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.
EEC Wiring Harnesses