04/09/21
Message Overview:
Message Description:
Proximity-Sensor Electronic Unit (PSEU) detects an internal SHORT circuit within the Proximity Sensor PX45, Baggage Bay Door Closed or in the wiring to the proximity sensor is shorted to the aircraft.
Possible Causes:
- Proximity Sensor Electronic Unit (PSEU) (A9)
- Baggage Door Closed Proximity Sensor (PX45)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| 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 |
| Functional Test of the Proximity-Sensor Electronic Unit (PSEU) | AMM 32-61-09-720-801 |
| Operational Test of the Door Sensors | AMM 52-71-00-710-801 |
| Removal of the Baggage-Door Closed Proximity-Sensor | AMM 52-71-05-000-801 |
| Installation of the Baggage-Door Closed Proximity-Sensor | AMM 52-71-05-400-801 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Pull and reset the PSEU gear system breakers (CB1-C13, CB1-C14, CB2-C13,CB2-C14), recheck the system for the fault.
- Remove the PSEU from its rack and disconnect the connector SP118 from PX45. Verify the wiring from the PX45 SP112 PIN A2 to ground and from PX45 SP112 PIN B2 to ground. The wires should be open to ground.
- If the wiring checks good, download and have field service review the PSEU NVM. Further troubleshooting will depend on results of the PSEU NVM.
- If the fault is still there, replace PX45 per the installation procedure, and then check the sensor out.
- If the fault is still there, replace the PSEU.
- Perform functional check of the proximity sensor electronic unit.
- Do close out.




