03/16/26
Message Overview:
Message Name:
SURGE BLEED VALVE B 1B
Message Code:
B3-303771
Associated CAS:
| Reporting LRU: | L ENG SBV B |
| System Description: | 72-30-00 - Compressor Section |
| Schematic Diagram: | SSM 77-10-00-101 - Power |
| Wiring Diagram: | None |
Message Description:
Left engine surge bleed valve B fault 1B.
[MCID 0410]
SBV B 1B.
A fault in the SBV B harness between the SBV B and the ECU B was sensed.
Possible Causes:
- Wiring Harness (W5)
- Wiring Harness (W4)
- Surge Bleed Valve (SBV) B
- Full Authority Digital Engine Control Unit (FADEC) Electronic Control Unit B (ECU) (A43)
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Full Throttle Blog/Forum Articles/Infoservice/Newsletter: None
Flight Operation Notifications Manual (FONM): None
NOTES:
- If the L or R ENG MINOR FAULT CAS message is shown with this fault, this is a Short Term dispatch (STD) fault and is subject to correction outlined in the Honeywell LEMM SUBTASK 5-10-00-200-003.
- If a L or R FADEC FAIL CAS message is shown, this is a No Dispatch (ND) fault and is subject to correction outlined in the Honeywell LEMM SUBTASK 5-10-00-200-003.
- Check for the following MDC messages displayed with the fault: X-channel bus 1A (MCID 0905), X-channel bus 1B (MCID 0906), X-channel discrete 1A (MCID 0933), X-channel discrete 1B (MCID 0934). If any of the above MCID codes are posted, correct the cross channel faults first.
Issues with the N1 shutoff (Broken Shaft Connector), or bleed surge valves, contact Honeywell FSR and find out about status of Dash 12 W5 harness. Ref Honeywell S/B AS907-76-9011. Most likely tied to connector pin friction or loose connector.
Quick Links:
| General Setup for Maintenance | |
|---|---|
| Standard Aircraft Configuration for Maintenance | AMM 12-00-00-867-803 |
| Connect Electrical Power to the Aircraft | AMM 24-00-00-861-801 |
| Remove Electrical Power from the Aircraft | AMM 24-00-00-861-802 |
| Electrical/Electronic Safety Precautions | AMM 24-00-00-910-801 |
| Electrostatic Discharge Safety Precautions | AMM 24-00-00-910-802 |
| Maintenance Tasks | |
| Removal of the Trim-Surge Bleed Valves | AMM 75-31-06-000-801 |
| Installation of the Trim-Surge Bleed Valves | AMM 75-31-06-400-801 |
| Removal of the Engine Electronic Control Unit (ECU) | AMM 76-10-05-000-801 |
| Installation of the Engine Electronic Control Unit (ECU) | AMM 76-10-05-400-801 |
Troubleshooting Recommendations:
- MCID 0410 fault only is present, troubleshoot using the following steps for aircraft and engine fault isolation with reference to the Light Engine Maintenance Manual TASK 72-00-00-810-058.
- Reset and reboot the ECU to recheck the MDC MCID for the posted fault.
- Remove the connector on the ECU 1B, W3P9 and inspect for burned or pushed back pins/sockets, particularly pins 54 and 49, inspect for damage, then check the following segments per the table, repair wiring if required per the wiring manual standard practices
- On W3P9 pins 54 and 49, document the resistance value down through the coil of the Solenoid B of Surge Bleed Valve B. Resistance should be 10 to 80Ω, IAW Honeywell LMM.
- Remove the W3 harness on the bottom of the engine W3P12. Consider ringing out the SBV B, particularly on pin 8 and 9 of W5J1.
- Check the connection on the SBV B by examining W5P6.
From To Value W3P9 Pin 54 W3P9 Pin 49 10 to 80 Ω W5J1 Pin 8 W5J1W5J1 Pin 9 10 to 80 Ω W5P6 Pin 3 W5P6 Pin 4 10 to 80 Ω - If the wiring is good and the valve solenoid resistance is out of limits, replace SBV B Main Surge Bleed Valve IAW AMM TASK 75-31-05-000-801, TASK 75-31-05-400-801.
- If the wiring and SBV check good, consider swapping the A and B ECUs for the left engine, remove and replace IAW AMM TASK 76-10-05-000-801, TASK 76-10-05-400-801.




