03/16/21
Message Overview:
Message Description:
Proximity Sensor Electronic Unit detects that the discrete output to the Retract Valve has an unreasonable load connected.
Possible Causes:
- Landing-Gear Selector Valve (V9)
- Junction Box 4 (JB4) Circuit-Card 2 (JB4-DB2)
- Proximity Sensor-Electronic Unit (PSEU) (A9)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Junction Box JB4 Circuit-Cards | AMM 24-63-13-000-803 |
| Installation of the Junction Box JB4 Circuit-Cards | AMM 24-63-13-400-803 |
| Operational Test of Junction Box JB4 Card 2 | AMM 24-63-13-710-802 |
| Operational Test of the Extension and Retraction System | AMM 32-30-00-710-801 |
| Removal of the Landing-Gear Selector Valve | AMM 32-31-01-000-801 |
| Installation of the Landing-Gear Selector Valve | AMM 32-31-01-400-801 |
| 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:
- Do wiring check from the JB4 connector JB4AP1 Pin 14F to the PSEU connector A9CP1 Pin 4C. Repair as required.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Do wiring check from the JB4 connector JB4AP1 Pin 14B to the PSEU connector A9CP1 Pin 5C. Repair as required.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Do wiring check from the JB4 connector JB4AP1 Pin 13H to the Retract Valve connector V9P1 Pin B. Repair as required.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace the Retract Valve V9.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace the Circuit Board 2 of the JB4.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace the PSEU.
- Do close out.