Fault Message:

L CH A TURB O'HEAT WRG/PROBE RNG MA

Fault Code:

7327627LBR

Associated CAS:

L FADEC FAULT
(Advisory)

There is an open or short circuit in the interface wiring or the Turbine Overheat-Detection Thermocouple. During Engine operation the Turbine Overheat-Detection Circuits are continuously monitored by the Full-Authority Digital Engine-Controller (FADEC).

• Turbine Overheat-Detection Thermocouple
• Left Engine Electronic Controller (EEC)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

1. Perform a visual inspection of the turbine overheat-detection system. Inspect for damage and proper installation.
   NOTE: Look specially for signs of damage adjacent to clip locations.

   1. If damage or defect is found, rectify or repair as required and do close out.
   2. If damage or defect is not found, continue with next step.

2. Disconnect the EEC connector (P1044) and the bypass duct connectors (P1030 and J1030). Disconnect the interface wiring at the terminal blocks TB2114 and TB2115 and at the ground connector (GC2106). Perform a visual inspection of the associated wiring and connectors for damage between the connectors and the terminal blocks.
   NOTE: Look specially for signs of chafing adjacent to clip locations, condition of connector pins and wiring kink or strain.

   1. If defects are found, rectify or repair as required and do close out.
   2. If defects are not found, continue with next step.

3. Perform a continuity check between the terminal blocks TB2114 and TB2115 (Chromel and Alumel terminal lugs) and the connector P1030 as follows:

   From	To	Result
   TB2114	P1030-30
   TB2115	P1030-31

   1. If there is no continuity, repair defective wiring as required and do close out.
   2. If there is continuity, continue with next step.

4. Perform a continuity check between the connectors J1030 and P1044 as follows:

   From	To	Result
   J1030-30	P1044-52
   J1030-31	P1044-31

   1. If there is no continuity, repair defective wiring as required and do close out.
   2. If there is continuity, continue with next step.

5. Perform a insulation resistance check of the wiring between the bypass duct and the terminal blocks as follows:

   From	To	Resistance Value	Result
   P1030-30	Ground	20 MΩ or more
   P1030-31	Ground	20 MΩ or more

   1. If the resistance value is less than the value specified in the table or if there is a short to ground, repair defective wiring as required and do close out.
   2. If there is no continuity or resistance value is as specified in the table, continue with next step.

6. Perform a insulation resistance check of the wiring between the EEC and the bypass duct connector (P1044) as follows:

   From	To	Resistance Value	Result
   P1044-52	Ground	20 MΩ or more
   P1044-31	Ground	20 MΩ or more

   1. If the resistance value is less than the value specified in the table or if there is a short to ground, repair defective wiring as required and do close out.
   2. If there is no continuity or resistance value is as specified in the table, continue with next step.

7. Replace turbine overheat-detection thermocouple. Is the fault still present?

   1. If YES, continue with next step.
   2. If NO, do close out.

8. Swap both EECs to confirm faulty unit and replace if required.
9. Do close out.