Message Name:

HS1L - HI LEVEL SENSOR/WRG

Message Code:

2844670PK

Associated CAS:

L WING FULL
(Caution)

HS1L SENSOR FUEL HI LVL/WRG FAULT shows when:

• HS1L High-Level Sensor or interface is out of range
• Sensor circuit is open
• Sensor circuit is shorted
• Sensor is contaminated
OR,
• The Fuel Management and Quantity Gauging Computer (FMQGC) automatic calibration test failed (Circuit Fault)

• Left Wing Fuel Tank High Level Sensor (HS1L) (C1)
• Fuel Management and Quantity Gauging Computer (FMQGC) (A47)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Full Throttle Blog/Forum Articles/Infoservice/Newsletter: None

Flight Operation Notifications Manual (FONM): None

1. On the CAIMS PMAT do the steps that follow:

   1. Select CAIMS.
   2. Select System Diagnostics.
   3. Select 28-00 FUEL.
   4. Select Computer (FMQGC CH A(B)).
   5. Select LRU TEST.
   6. Select LEFT WING HIGH LEVEL DATA CH A.

2. Does HS1L (Inboard) sensor show a Circuit Fault?

   1. If NO, then go to step 9.
   2. If YES, then continue with the next step.

3. Is there is a group of probes that are out of range?

   1. If NO, then go to step 9.
   2. If YES, then continue with the next step.

4. Gain access under the number 2 LH wing fixed leading edge.
5. Inspect the excitation feed wire LTP3. Move the wire around while someone else watches the PF capacitance value on the CAIMS PMAT.
6. Does the capacitance PF values move around drastically while moving shaking the wiring and connections on the CAIMS PMAT?

   1. If YES, then repair the wiring or the connector and do close out.
   2. If NO, then continue with the next step.

7. Disconnect LTP3. Perform a wiring check on LTP3 under the number 2 LH wing fixed leading edge as follows:
   NOTE: Move the wire around to check for wire fractures or a bad connector.

   From	To	Expected Result	Result
   LTP3 Center pin	Ground	5 VAC ±0.5
   LTP3 Center pin	Shield	Open

   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.

8. Re-Connect LTP3.
9. Re-rack the FMQGC and access CAIMS active faults. Is the CAIMS message (2844670PK HS1L SENSOR FUEL HI LVL/WRG) still present?

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

10. Disconnect LTP1. Perform a wiring check on LTP1 under the number 2 LH wing fixed leading edge as follows:
    NOTE: Move the wire around to check for wire fractures or a bad connector.

    From	To	Expected Result	Result
    LTP1-12	Ground	Continuity
    LTP1-12	Shield	Open

    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.

11. Gain access to probe Left hand high level sensor (C1).
12. Visually inspect the sensor for contamination and condition.

    1. If the inspection results are not good, rectify or replace high level sensor as required and do close out.
    2. If the inspection results are good, continue with the next step.

13. Gain access to connector LTJ1 inside the LH wing.
14. Disconnect connectors LTJ3 and LTJ1. Inspect the connector for internal fuel or corrosion and general condition.
    NOTE: Any black discoloring inside the connector should be cleaned and or replace the connector.
15. Re-connect connectors LTJ3 and LTJ1.
16. Clean the high level sensor per (AMM 28-41-00-110-801) Cleaning of the Fuel Management and Quantity Gauging System (FMQGS) Components.
17. Close access to the fuel tank.
18. Access CAIMS active faults. Is the CAIMS message (2844670PK HS1L SENSOR FUEL HI LVL/WRG) still present?

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

19. Remove and replace the FMQGC (A47).
20. Do close out.