Fault Message:

LVDT EXCITATION/ SFCU#1/ WRG

Fault Code:

2751260STD

Associated CAS:

None

When one of the following conditions occurs:

• The output voltage is not within the permitted range
• The output current is not within the permitted range

• Linear Variable Displacement Transducer (LVDT) (MT68)
• Linear Variable Displacement Transducer (LVDT) (MT69)
• Linear Variable Displacement Transducer (LVDT) (MT70)
• Linear Variable Displacement Transducer (LVDT) (MT71)
• Slat Flap Control Unit (SFCU) 1 (A124)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

NOTE: You may attempt to clear the fault: On the EMS CDU, select CTRL function and SLAT/FLAP RESET. Wait at least one minute after SFCU reset to allow self-test to run.

1. Remove SFCU 1 and perform a resistance check between the flap LVDTs and the SFCU as follows:
   NOTE: Performing this resistance check will verify the Associated Wiring in addition to the resolver.
   LVDT 1:

   From	To	Expected Result	Result
   A124CP1-37	A124CP1-25	120 to 150 Ohms
   A124CP1-54	A124CP1-67	250 to 280 Ohms
   A124CP1-54	A124CP1-66	110 to 130 Ohms
   A124CP1-67	A124CP1-66	140 to 160 Ohms

   LVDT 2:

   From	To	Expected Result	Result
   A124CP1-36	A124CP1-24	120 to 150 Ohms
   A124CP1-14	A124CP1-27	250 to 280 Ohms
   A124CP1-14	A124CP1-15	110 to 130 Ohms
   A124CP1-27	A124CP1-15	140 to 160 Ohms

   LVDT 3:

   From	To	Expected Result	Result
   A124CP1-35	A124CP1-23	120 to 150 Ohms
   A124CP1-29	A124CP1-42	250 to 280 Ohms
   A124CP1-29	A124CP1-41	110 to 130 Ohms
   A124CP1-42	A124CP1-41	140 to 160 Ohms

   LVDT 4:

   From	To	Expected Result	Result
   A124CP1-48	A124CP1-49	120 to 150 Ohms
   A124CP1-39	A124CP1-52	250 to 280 Ohms
   A124CP1-39	A124CP1-51	110 to 130 Ohms
   A124CP1-52	A124CP1-51	140 to 160 Ohms

   1. If one or more measurement is out of tolerance, continue with next step.
   2. If all resistance values are within tolerance, go to step 3.

2. Access and remove the associated LVDT. Perform a wiring check between SFCU 1 and the associated LVDT. Check for end to end continuity and for short circuit to ground.

   1. If wiring checks are not good, repair defective wiring as required and do close out.
   2. If wiring checks are good, continue with next step.

3. Swap SFCU 1 with SFCU 2.

   1. If system checks are good, replace SFCU 1 and do close out.
   2. If fault remains, continue with next step.

4. Replace the LVDT.
5. Do close out.