Mass Flow Meter and Fuel Metering Valve Signal Disagreement

TASK 73-31-00-810-812-A
Mass Flow Meter and Fuel Metering Valve Signal Disagreement

1. Possible Causes

XMTR - FUEL FLOW [4010KS]
INTEGRATED FUEL PUMP AND CONTROL [4360KS]
W04 HARNESS [4088KS]
WC08 HARNESS-CORE [4094KS]
W03 HARNESS [4087KS]
[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 71-00-00-720-816	Test No. 17 - Above Idle Test
AMM 71-00-00-860-814	Shutdown of the Engine
AMM 73-11-01-000-801	Removal of the Integrated Fuel Pump and Control (IFPC)
AMM 73-11-01-400-801	Installation of the Integrated Fuel Pump and Control (IFPC)
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 73-21-68-000-802	Removal of the EEC Wiring Harness (WC08)
AMM 73-21-68-400-802	Installation of the EEC Wiring Harness (WC08)
AMM 73-31-21-000-801	Removal of the Fuel Flow Transmitter
AMM 73-31-21-400-801	Installation of the Fuel Flow Transmitter
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
Fuel Flow Transmitter Wiring Harness
Integrated Fuel Pump and Control Channel A Wiring Schematic
Integrated Fuel Pump and Control Channel B Wiring Schematic

3. Fault Confirmation
Subtask 73-31-00-710-086-A ** ON A/C NOT FOR ALL

A. Look at fault data from the previous leg report to confirm this fault has been set.

NOTE: The Electronic Engine Control (EEC) has detected the fuel flow transmitter and Fuel Metering Valve (FMV) do not agree within the normally acceptable range at cruise power. This fault condition will cause the EEC to only use the FMV position to calculate fuel flow which is a less accurate value than the fuel flow transmitter. The fuel flow transmitter is attached between fuel tubes FM01 and FM02 at the 3 o'clock position. The fuel flow transmitter circuit is connected to channel A of the EEC and the fuel flow value is cross talked to channel B inside the EEC. The FMV is a part of the Integrated Fuel Pump and Control (IFPC). The integrated fuel pump and control is mounted on top of the Main Gearbox (MGB) at the 4 o'clock position.

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 regularly, monitor the engine for reoccurring fault on subsequent flights.
(a) If the fault returns continue with the hard fault troubleshooting below.
(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 73-31-00-810-070-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) Replace XMTR - FUEL FLOW [4010KS] AMM 73-31-21-000-801 and AMM 73-31-21-400-801.
(a) Do the repair confirmation, refer to the Para. 4.B.
(3) If the fault continues:
(a) Replace INTEGRATED FUEL PUMP AND CONTROL [4360KS] AMM 73-11-01-000-801 and AMM 73-11-01-400-801.
(b) Do the repair confirmation, refer to the Para. 4.B.
(4) If the fault continues:
(a) Examine the W04 (4088KS) and WC08 (4094KS) harnesses and connector P3 (4000KS-P3) - EEC (4000KS), interconnect J108 (4111VC)/P108 (4111VC-A) and P27 (4010KS-P27)- fuel flow transmitter (4010KS), for problems which are possible between the EEC (4000KS) and the fuel flow transmitter (4010KS).
1 Inspect for harness damage.
2 Inspect for loose or damaged connectors.

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

3 If a problem is found with the harnesses or connectors:
a Replace W04 HARNESS [4088KS] AMM 73-21-64-000-802 and AMM 73-21-64-400-802, or
b Replace WC08 HARNESS-CORE [4094KS] AMM 73-21-68-000-802 and AMM 73-21-68-400-802.
c Do the repair confirmation, refer to the Para. 4.B.
(5) If no problems are found with the harnesses, use a PLIERS - JAWED, SOFT to disconnect electrical connector P3 (4000KS-P3) from the EEC (4000KS), interconnect J108 (4111VC)/P108 (4111VC-A) and connector P27 (4010KS-P27) from the fuel flow transmitter (4010KS).
(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 connector P3 (4000KS-P3) to the EEC (4000KS), interconnect J108 (4111VC)/P108 (4111VC-A) and connector P27 (4010KS-P27) to the fuel flow transmitter (4010KS).
(d) Do the repair confirmation, refer to the Para. 4.B.
(6) If the fault continues:
(a) Disconnect electrical connector P3 (4000KS-P3) from the EEC (4000KS), interconnect J108 (4111VC)/P108 (4111VC-A) and connector P27 (4010KS-P27) from the fuel flow transmitter (4010KS). Use a MULTIMETER - STANDARD to test the fuel flow transmitter (4010KS) circuits in the harnesses. Refer to Table 201. 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 201: Fuel Flow Transmitter Channel A Circuit Connector Contacts

W04 (4088KS) Harness P3 (4000KS-P3) EEC (4000KS) Connector Contacts	W04 (4088KS) Harness J108 (4111VC) Connector Contacts	WC08 (4094KS) Harness P108 (4111VC-A) Connector Contacts	WC08 (4094KS) Harness P27 (4010KS-P27) Fuel Flow Transmitter (4010KS) Connector Contacts
A	4	4	1
b	5	5	2
c	15	15	3

(b) If a problem is found with the harnesses or connectors:
1 Replace W04 HARNESS [4088KS] AMM 73-21-64-000-802 and AMM 73-21-64-400-802, or
2 Replace WC08 HARNESS-CORE [4094KS] AMM 73-21-68-000-802 and AMM 73-21-68-400-802.
3 Do the repair confirmation, refer to the Para. 4.B.
(7) If the fault continues:
(a) Disconnect the W04 (4088KS) harness connector P3 (4000KS-P3) - EEC (4000KS), interconnect J108 (4111VC)/P108 (4111VC-A), the WC08 (4094KS) harness and the integrated fuel pump and control (4360KS) connector P15 (4360KS-P15).
(b) Disconnect the W03 (4087KS) harness connector P4 (4000KS-P4) - EEC (4000KS) and connector P16 (4360KS-P16) - integrated fuel pump and control (4360KS). Test the integrated fuel pump and control FMV LDVT circuit. Refer to Table 202 and Table 203. 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 202: IFPC FMV LVDT Channel A Contacts

W04 (4088KS) Harness P3 (4000KS-P3) EEC (4000KS) Connector Contacts	W04 (4088KS) Harness J108 (4111VC) Connector Contacts	WC08 (4094KS) Harness P108 (4111VC-A) Connector Contacts	WC08 (4094KS) Harness P15 (4360KS-P15) IFPC (4360KS) Connector Contacts
z	10	10	8
h	11	11	19
LL	1	1	7
KK	2	2	18
PP	3	3	17

Table 203: IFPC FMV LVDT Channel B Contacts

W03 (4087KS) Harness P4 (4000KS-P4) EEC (4000KS) Connector Contacts	W03 (4087KS) Harness P16 (4360KS-P16) IFPC (4360KS) Connector Contacts
z	8
h	19
LL	7
KK	18
PP	17

(8) If a problem is found with the W04 (4088KS) harness or connectors:
(a) Replace W04 HARNESS [4088KS] AMM 73-21-64-000-802 and AMM 73-21-64-400-802.
(b) Do the repair confirmation, refer to the Para. 4.B.
(9) If a problem is found with the WC08 (4094KS) harness or connectors:
(a) Replace WC08 HARNESS-CORE [4094KS] AMM 73-21-68-000-802 and AMM 73-21-68-400-802.
(b) Do the repair confirmation, refer to the Para. 4.B.
(10) If a problem is found with the W03 (4087KS) harness or connectors:
(a) Replace W03 HARNESS [4087KS] AMM 73-21-63-000-802 and AMM 73-21-63-400-802.
(b) Do the repair confirmation, refer to the Para. 4.B.
(11) If the fault continues:
(a) Replace [4000KS] AMM 73-21-01-000-801 and AMM 73-21-01-400-801.
(b) Do the repair confirmation, refer to the Para. 4.B.

Subtask 73-31-00-710-087-A ** ON A/C NOT FOR ALL

B. Repair Confirmation
(1) Do an above idle test AMM 71-00-00-720-816 for engine operation at 50 percent N1 speed.
(a) Shutdown the engine AMM 71-00-00-860-814.
(b) Do a check of the ground scanning report to confirm repair of this fault.

5. Close-up
Subtask 73-31-00-860-063-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 04:36:30 UTC