Mass Flow Meter Electrical Failure Channel A

TASK 73-31-00-810-811-A
Mass Flow Meter Electrical Failure Channel A

1. Possible Causes

XMTR - FUEL FLOW [4010KS]
W04 HARNESS [4088KS]
WC08 HARNESS-CORE [4094KS]
[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 71-00-00-860-814	Shutdown of the Engine
AMM 71-00-00-860-822	Start the Engine (Normal Manual Start)
AMM 71-00-00-860-823	Start the Engine (Normal Automatic Start)
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 73-21-64-000-802	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
W04/WC08 Interconnect Wiring Harness
Fuel Flow Transmitter Wiring Harness
Fuel Flow Transmitter Wiring Schematic

3. Fault Confirmation
Subtask 73-31-00-710-085-A ** ON A/C NOT FOR ALL

A. Test
(1) Do an engine run to idle to confirm repair of this fault AMM 71-00-00-860-822 or AMM 71-00-00-860-823.
(a) Shutdown the engine AMM 71-00-00-860-814.
(b) On Multipurpose Control and Display Unit (MCDU) screen:
1 Check if the fault is displayed on ground scanning report.

NOTE: The Electronic Engine Control (EEC) has detected the circuit for the fuel flow transmitter is out of rate or range in channel A. The fuel flow transmitter is mounted on the compressor intermediate case, located at the 4 o'clock position. The fuel flow transmitter circuit is connected to channel A of the EEC and cross linked to channel B inside the EEC.

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).

(2) If the maintenance message does not come back, examine the harnesses 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 message.
(3) If the maintenance message comes back (hard fault) in channel A, 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 73-31-00-810-069-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 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).
(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 harness 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 test given in Para. 3.
(3) If no problems are found with the harness, 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 test given in Para. 3.
(4) If the fault continues:
(a) Replace XMTR - FUEL FLOW [4010KS] AMM 73-31-21-000-801 and AMM 73-31-21-400-801.
(b) Do the test given in Para. 3.
(5) 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 1. 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: 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 test given in Para. 3.
(6) If the fault continues:
(a) Replace [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 73-31-00-860-062-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