RTT Feedback Proximity Sensor Signal Disagreement

TASK 73-13-00-810-810-A
RTT Feedback Proximity Sensor Signal Disagreement

1. Possible Causes

FUEL RETURN TO TANK MODULE [4082KS]
W03 HARNESS [4087KS]
W04 HARNESS [4088KS]
HARNESS-CORE,WC11 [4072KS]
[4000KS]

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	MULTIMETER - STANDARD
No specific	1	PLIERS - JAWED, SOFT

B. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 71-00-00-810-834-A	General Troubleshooting Guidelines for Additional Troubleshooting Information
TSM TASK 71-00-00-810-835-A	Component and Harness Intermittent Troubleshooting Procedure for Guidance Troubleshooting Intermittent Faults
AMM 70-70-00-910-803	SPOP 6 - Cleaning of the Contact Points and Wiring Harnesses
AMM 73-13-03-000-801	Removal of the Fuel Return To Tank (RTT) Valve
AMM 73-13-03-400-801	Installation of the Fuel Return To Tank (RTT) Valve
AMM 73-21-00-710-806	Test No.7 - EEC Operation Test (Self Test)
AMM 73-21-01-000-801	Removal of the Electronic Engine Control (EEC)
AMM 73-21-01-400-801	Installation of the Electronic Engine Control (EEC)
AMM 73-21-63-000-802	Removal of the Electronic Engine Control (EEC) Wiring Harness (W03)
AMM 73-21-63-400-802	Installation of the Electronic Engine Control (EEC) Wiring Harness (W03)
AMM 73-21-64-000-802	Removal of the Electronic Engine Control (EEC) Wiring Harness (W04)
AMM 73-21-64-400-802	Installation of the Electronic Engine Control (EEC) Wiring Harness (W04)
AMM 73-21-70-000-802	Removal of the Electronic Engine Control (EEC) Wiring Harness (WC11)
AMM 73-21-70-400-802	Installation of the Electronic Engine Control (EEC) Wiring Harness (WC11)
AMM 78-36-00-010-802	Opening of the Thrust Reverser Cowl-Doors
AMM 78-36-00-410-802	Closing of the Thrust Reverser Cowl-Doors
EEC Wiring Harnesses
W03/WC10 Interconnect Wiring Harness
Fuel Return to Tank Valve Wiring Harness
Fuel Return to Tank Valve Wiring Schematic
W03/W04 Wiring Harness Interconnects

3. Fault Confirmation
Subtask 73-13-00-710-059-A ** ON A/C NOT FOR ALL

A. Do the EEC system interactive test to confirm this fault. Refer to FADEC self test AMM 73-21-00-710-806.

NOTE: The Electronic Engine Control (EEC) has detected the Return To Tank (RTT) valve proximity sensor signals in channel A and channel B do not agree. The RTT valve proximity sensor is part of the RTT valve. The RTT valve is located on the thermal management system manifold at the 8 o'clock position, aft of the main gearbox.

Refer to the general troubleshooting guidelines for additional troubleshooting information (Ref. TSM TASK 71-00-00-810-834).
Refer to the component and harness intermittent troubleshooting procedure for guidance troubleshooting intermittent faults (Ref. TSM TASK 71-00-00-810-835).

(1) If the maintenance message does not come back, examine the harness and electrical connectors as described in the component and harness intermittent fault isolation procedure (Ref. TSM TASK 71-00-00-810-835).
(a) If no problems are found, return the engine to service. Monitor the engine for reoccurring maintenance messages. Do the component and harness maintenance message troubleshooting procedure to fix the fault (Ref. TSM TASK 71-00-00-810-835).
(2) If the maintenance message comes back (hard fault), go to the Para. Fault Isolation.

4. Fault Isolation

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.

WARNING: REFER TO THE MSDS FOR ALL MATERIAL USED AND THE MANUFACTURER'S SAFETY INSTRUCTIONS FOR ALL EQUIPMENT USED. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.

CAUTION: MAKE SURE YOU REMOVE ELECTRICAL POWER FROM THE EEC BEFORE YOU REMOVE THE ELECTRICAL CONNECTORS. IF YOU DO NOT OBEY THIS INSTRUCTION, DAMAGE TO THE EEC CAN OCCUR.

Subtask 73-13-00-810-059-A ** ON A/C NOT FOR ALL

A. If there is confirmation of the fault:
(1) Open the thrust reverser cowl-doors AMM 78-36-00-010-802.
(2) Examine the W03 (4087KS), W04 (4088KS) and WC11 (4072KS) harnesses and connectors P3 (4000KS-P3) and P4 (4000KS-P4) - EEC (4000KS), interconnect P106 (4100VC-A)/J106 (4100VC), interconnect J105 (4108VC)/P105 (4108VC-A) and connector P68 (4082KS- P68) - Fuel RTT valve (4082KS), for problems which are possible between the EEC (4000KS) and the fuel RTT valve (4082KS).
(a) Inspect for harness damage.
(b) Inspect for loose or damaged connectors.

NOTE: Loose connectors must be disconnected and examined for further wear or damage.

(c) If a problem is found with the harnesses or connectors:
1 Replace W03 HARNESS(4087KS) AMM 73-21-63-000-802 and AMM 73-21-63-000-802, or
2 Replace W04 HARNESS(4088KS) AMM 73-21-64-000-802 and AMM 73-21-64-400-802, or
3 Replace WC11 HARNESS-CORE(4072KS) AMM 73-21-70-000-802 and AMM 73-21-70-400-802.
4 Do the test given in Para. 3.
(3) If no problems are found with the harnesses or the fault continues, use a PLIERS - JAWED, SOFT to disconnect electrical connectors P3 (4000KS-P3) and P4 (4000KS-P4) from the EEC (4000KS), interconnect P106 (4100VC-A)/J106 (4100VC), interconnect J105 (4108VC)/P105 (4108VC-A) and connector P68 (4082KS-P68) from the fuel RTT valve (4082KS).
(a) Examine the pins and sockets (contacts) for alignment and damage. Look for contacts pushed rearward into the connector face. Replace parts as necessary.
(b) Clean the contacts with contact cleaner and clean cloth per SPOP 6. Blow dry with air (at less than 30 psi) across the connector face AMM 70-70-00-910-803.
(c) Reconnect electrical connectors P3 (4000KS-P3) and P4 (4000KS-P4) to the EEC (4000KS), interconnect P106 (4100VC-A)/J106 (4100VC), interconnect J105 (4108VC)/P105 (4108VC-A) and connector P68 (4082KS-P68) to the fuel RTT valve (4082KS).
(d) Do the test given in Para. 3.
(4) If the fault continues:
(a) Replace FUEL RETURN TO TANK MODULE [4082KS] AMM 73-13-03-000-801 and AMM 73-13-03-400-801.
(b) Do the test given in Para. 3.
(5) If the fault continues:
(a) Disconnect electrical connectors P3 (4000KS-P3) and P4 (4000KS-P4) from the EEC (4000KS), interconnect P106 (4100VC-A)/J106 (4100VC), interconnect J105 (4108VC)/P105 (4108VC-A) and connector P68 (4082KS-P68) from the fuel RTT valve (4082KS). Use a MULTIMETER - STANDARD to test the fuel RTT valve (4082KS) proximity sensor circuits in the harnesses. Refer to Table 1 and Table 2. Look for:
1 Wire-to-wire shorts
2 Shorts to ground
3 Continuity (less than 5 ohms resistance).

NOTE: A short to ground is found when the resistance is less than 100 000 (100K) ohms.

Table 1: RTT Valve Sensor Channel A Connector Contacts

W04 (4088KS) Harness P3 EEC(4000KS) Connector Contacts	W04 (4088KS) Harness J105 (4108VC) Connector Contacts	WC11 (4072KS) Harness P105 (4108VC-A) Connector Contacts	WC11 (4072KS) Harness P68 (4082KS-P68) fuel RTT valve (4082KS) Connector Contacts
AA	23	23	4
i	24	24	14
K	25	25	5
J	26	26	15

Table 2: RTT Valve Sensor Channel B Connector Contacts

W03(4087KS) Harness P4 (4000KS-P4) EEC(4000KS) Connector Contacts	W03(4087KS) Harness P106 (4100VC-A) Connector Contacts	W04(4088KS) Harness J106 (4100VC) Connector Contacts	W04(4088KS) Harness J105 (4108VC) Connector Contacts	WC11(4072KS) Harness P105 (4108VC-A) Connector Contacts	WC11(4072KS) Harness P68 (4082KS-P68) Fuel RTT Valve(4082KS) Connector Contacts
AA	46	46	19	19	8
i	47	47	20	20	19
K	48	48	21	21	7
J	49	49	22	22	18

(b) If a problem is found with the harnesses or connectors:
1 Replace W03 HARNESS [4087KS] AMM 73-21-63-000-802 and AMM 73-21-63-400-802, or
2 Replace W04 HARNESS [4088KS] AMM 73-21-64-000-802 and AMM 73-21-64-400-802, or
3 Replace HARNESS-CORE,WC11 [4072KS] AMM 73-21-70-000-802 and AMM 73-21-70-400-802.
4 Do the test given in Para. 3.
(6) If the fault continues:
(a) Replace the [4000KS] AMM 73-21-01-000-801 and AMM 73-21-01-400-801.
(b) Do the test given in Para. 3.

5. Close-up
Subtask 73-13-00-860-059-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(a) Close the thrust reverser cowl-doors AMM 78-36-00-410-802.

[Rev.8 from Aug 2018] 2026.04.04 04:36:37 UTC