03/15/21
Message Overview:
Message Description:
Right Main Landing Gear Uplock Sensor PX04 signal conditioning failed.
Possible Causes:
- Proximity-Sensor Electronic Unit (PSEU)
- Right Main Landing-Gear Uplock Proximity-Sensor(PX04)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Operational Test of the Proximity Sensors | AMM 32-61-00-710-801 |
| Functional Test of the Proximity Sensors | AMM 32-61-00-720-801 |
| 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 |
| Functional Test of the Proximity-Sensor Electronic Unit (PSEU) | AMM 32-61-09-720-801 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
| Electrical Connectors - Maintenance Practice - ALL | SPM 20-20-00-02 |
Troubleshooting Recommendations:
- Pull and reset the PSEU gear system breakers(CB1-C13, CB1-C14), (CB2-C13, CB2-C14).
- If system checks are good, do close out.
- If fault remains, continue with next step.
- If PX01, PX10, PX13 and PX16 also indicate Signal Conditioning Failure, troubleshoot these sensors for a short to ground. Repair as required.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace PX04.
NOTE: Sensor resistance should be made with a meter using a < 10 mA supply of current. Never apply voltage through a sensor! Current will magnetize the sensors rendering it unreliable. Sensor resistance is typically 11 to 13 Ω.- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace PSEU if failure is on PX04 only and the NVM download does not identify external inputs as the fault.
- Do close out.
