09/16/19
Message Overview:
Fault Message:
EGT SENSOR [CIRCUIT 1 VOLTS OUT LO]
Fault Code:
4960151APU
Associated CAS:
| Reporting LRU: | Auxiliary Power Unit (APU) Full Authority Digital Engine-Controller (FADEC) |
| System Description: | 49-60-00 |
| Schematic Diagram: | 49-61-00 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wiring Diagram: | 49-61-01 [ Global Express ] [ G5000 ] [ Global XRS ] |
Fault Description:
The Auxiliary Power Unit (APU) Full Authority Digital Engine-Controller (FADEC) detected a failure in the Exhaust-Gas Temperature (EGT) Sensor circuit 1.
Possible Causes:
- Exhaust-Gas Temperature (EGT) Sensor (TC1)
- Auxiliary Power Unit (APU) Full Authority Digital Engine-Controller (FADEC) (A108)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Loss of one EGT sensor will not affect APU operation; however an advisory (Cyan) APU FAULT will be displayed on the EICAS primary page, on ground or in flight. Loss of both EGT will cause an APU SHUTDOWN on ground and an APU FAULT message in flight. EGT sensor can be replaced separately and does not require any adjustments or calibration. It is an 'on condition' component requiring no service.Gas Turbine Auxiliary CMM 49-24-35.
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 Exhaust Gas Temperature (EGT) Sensor | AMM 49-61-05-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Exhaust Gas Temperature (EGT) Sensor | AMM 49-61-05-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Gas Turbine Auxiliary | CMM 49-24-35 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 [ Global Express ] [ G5000 ] [ Global XRS ] |
Troubleshooting Recommendations:
- Perform continuity check at the EGT 1 sensor receptacle TC1-1 as follows:
From To Expected Result Result TC1-A TC1-B >20 ohms TC1-C TC1-D >20 ohms - If there is no continuity, go to step 5.
- If there is continuity, continue with next step.
- Perform wiring checks between sensors EGT 1 (TC1P1) and APU FADEC on connector (A108BP1) as follow:
From To Result Chromel (+) A108BP1-K5 Alumel (-) A108BP1-K6 - If wiring checks are not good, repair defective wiring as required and do close out.
- If wiring checks are good, continue with next step.
- Perform wiring checks between APU firewall (J802) and the EGT 1 (TC1) sensor as follow:
From To Expected Result Result J802-11 Alumel (-) <6 Ohms J802-12 Chromel (+) <6 Ohms - If wiring checks are not good, repair defective wiring as required and do close out.
- If wiring checks are good, continue with next step.
- Perform wiring checks between APU firewall (J802) and the APU FADEC connector (A108BP1) as follow:
From To Expected Result Result J802-11 A108BP1-K6 <11 Ohms J802-12 A108BP1-K5 <11 Ohms - If wiring checks are not good, repair defective wiring as required and do close out.
- If wiring checks are good, continue with next step.
- Replace EGT 1.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace APU FADEC.
- Do close out.