04/12/21
Message Overview:
Message Name:
OPEN/SHORT - SPEED SENSOR/CKT 1 WRG
Message Code:
4960265APU
Associated CAS:
| Reporting LRU: | Full-Authority Digital Engine-Controller (FADEC) |
| System Description: | 49-60-00 |
| Schematic Diagram: | 49-61-00 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wiring Diagram: | 49-12-01 [ Global Express ] [ G5000 ] [ Global XRS ] 49-61-01 [ Global Express ] [ G5000 ] [ Global XRS ] |
Message Description:
Speed Sensor 1 Built-In Test signal in the Full-Authority Digital Engine-Controller (FADEC) is set (TRUE) this shows a possible short or open in the Speed Sensor or engine branched wiring harness.
Possible Causes:
- Auxiliary Power Unit (APU) Full-Authority Digital Engine-Controller (FADEC) (A108)
- Speed Sensor (MT4)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Notice To Operators (NTO): None
Flight Operation Notifications Manual (FONM): None
If CAS message is not active, verify stored faults on CAIMS.
Quick Links:
| Removal of the Engine Branched Wiring-Harness | AMM 49-12-01-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Engine Branched Wiring-Harness | AMM 49-12-01-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of the Full-Authority Digital Engine-Controller (FADEC) | AMM 49-61-01-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Full-Authority Digital Engine-Controller (FADEC) | AMM 49-61-01-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of the Speed Sensor | AMM 49-61-17-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Speed Sensor | AMM 49-61-17-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 [ Global Express ] [ G5000 ] [ Global XRS ] |
Troubleshooting Recommendations:
- Perform wiring checks of the engine branched wiring harness.
- If wiring checks are not good, repair defective wiring as required and do close out.
- If wiring checks are good, continue with next step.
- Disconnect the MT4P1 connector from the speed sensor inspecting connector and sensor for contamination or damage.
- If there is contamination or damage, repair or replace as required and do close out.
- If there is no contamination or damage, continue with next step.
- Perform a continuity check as follows:
From To Expected Result Result MT4P1-A MT4P1-B 54.08-81.12 Ω - If resistance is not as mentioned above, go to step 6.
- If resistance is as mentioned above, continue with next step.
- Perform wiring checks between connector P802 on APU firewall and speed sensor (MT4P1) as follow:
From To Expected Result Result P802-13 MT4P1-A <1 Ω P802-14 MT4P1-B <1 Ω - If the resistance is not as mentioned above, go to step 6.
- If resistance is as mentioned above, continue with next step.
- Remove FADEC and perform wiring checks between P802 connector and the FADEC rack A108 as follow:
From To Expected Result Result J802-13 A108AP1-G11 <3 Ω J802-14 A108AP1-H11 <3 Ω - If the resistance is not as mentioned above, go to step 6.
- If resistance is as mentioned above, continue with next step.
- Replace speed sensor.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace FADEC.
- Do close out.
