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(WARNING)
RED MESSAGE (CAUTION)
AMBER MESSAGE (ADVISORY)
CYAN MESSAGE (STATUS)
WHITE MESSAGE Require immediate crew attention. These messages are accompanied by flashing master warning, triple chime attenson with or without voice message or dedicated tone. Require immediate crew awareness and future crew action may be required in the form of alternate system selection or performance limitation. These message are accompanied by flashing master caution and a single chime. Indicate safe or normal system operation which require crew awareness, over and above the dark cockpit philosophy. Indicate minor failures or reduction in systems capability, which require no crew action.

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11/20/25

Message Overview:

Message Name:

LMLG WOW2 OPEN

Message Code:

B3-007482

Associated CAS:

PROX SYS FAULT
(Advisory)

Reporting LRU: PSEU
System Description: 32-60-00 - Position and Warning
Schematic Diagram: 32-61-00-101 - Position Indication System
Wiring Diagram: 32-61-01-1 - Main-Landing-Gear Proximity Sensors (LHS)
32-61-09-1 - Proximity Sensor Electronic Unit (PSEU)
32-61-12-1 - Proximity Sensor Electronic Unit (POWER)

Message Description:

PSEU detects an OPEN circuit within the proximity sensor PX32 Left Main Landing Gear WOW2 or in the wiring to the proximity sensor or aircraft.

Possible Causes:

  • Proximity-Sensor Electronic Unit (PSEU) (A9)
  • Main Landing-Gear Weight-On-Wheels 2 Proximity-Sensor (LH) (PX32)
  • Associated Wiring

Troubleshooting Tips:

Advisory Wire/Service Bulletin: None

Full Throttle Blog/Forum Articles/Infoservice/Newsletter: None

Flight Operation Notifications Manual (FONM): None

Quick Links:

Standard Aircraft Configuration for Maintenance AMM 12-00-00-867-803
Electrical/Electronic Safety Precautions AMM 24-00-00-910-801
Electrostatic-Discharge Safety Precautions AMM 24-00-00-910-802
Operational Test of the Proximity Sensors AMM 32-61-00-710-801
Removal of the Main Landing-Gear (MLG) Proximity-Sensors AMM 32-61-01-000-801
Installation of the Main Landing-Gear (MLG) Proximity-Sensors AMM 32-61-01-400-801
Removal of the Proximity-Sensor Electronic Unit (PSEU) AMM 32-61-09-000-801
Installation of the Proximity-Sensor Electronic Unit (PSEU) AMM 32-61-09-400-801

Troubleshooting Recommendations:

  1. Pull and reset the PSEU gear system breakers (CB1-C13, CB1-C14, CB2-C13, CB2-C14).

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.

  2. Do AMM 32-61-00-710-801 - Operational Test of the Proximity Sensors and make sure that the health for the sensor shows ok.
  3. Are the results good?

    1. If YES, do the close out.
    2. If NO, continue with next step.

  4. Do wiring checks between PSEU A9CP1 (pins 10J, 9J) and J509 (pins 4, 5). 

    From To Expected Results Results
    A9CP1-10J J509-4 Continuity
    A9CP1-9J J509-5 Continuity

  5. Are the results good?

    1. If YES, continue with next step.
    2.  If NO, repair as required and do close out.

  6. Replace Proximity-Sensor PX32.
  7. Are the results good?

    1. If YES, do the close out.
    2. If NO, continue with next step

  8. Replace PSEU.
  9. Do close out.

60_lh_cbpnl60_rh_cbpnlpseu_location

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