Engine Fuel/Oil Heat Exchanger (FOHE) Bypass Valve Position Error Track Check in Channel B

TASK 79-21-00-810-830-A
Engine Fuel/Oil Heat Exchanger (FOHE) Bypass Valve Position Error Track Check in Channel B

1. Possible Causes

ENGINE FUEL/OIL HEAT EXCHANGER BYPASS VALVE [4112KS]
W04 HARNESS [4088KS]
W03 HARNESS [4087KS]
WC10 HARNESS-CORE [4011KS]
[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 73-21-63-000-802	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 73-21-69-000-802	Removal of the EEC Wiring Harness (WC10)
AMM 73-21-69-400-802	Installation of the EEC Wiring Harness (WC10)
AMM 79-21-09-000-801	Removal of the Engine Fuel/Oil Heat Exchanger Bypass Valve
AMM 79-21-09-400-801	Installation of the Engine Fuel/Oil Heat Exchanger Bypass Valve
W03/WC10 Interconnect Wiring Harness
Engine FOHE Bypass Valve Wiring Harness
Engine FOHE Bypass Valve Wiring Schematic
EEC Wiring Harness

3. Fault Confirmation
Subtask 79-21-00-710-077-A ** ON A/C NOT FOR ALL

A. 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.
(1) Shutdown the engine AMM 71-00-00-860-814.
(2) On Multipurpose Control and Display Unit (MCDU) screen, check if the fault is displayed on ground scanning report.

NOTE: The Electronic Engine Control (EEC) channel B has detected the engine Fuel/Oil Heat Exchanger (FOHE) bypass valve is either open when supposed to be closed or closed when supposed to be open. The engine FOHE bypass valve has a Linear Variable Differential Transducer (LVDT) circuit in channel A and Torque Motor (TM) circuits in channel A and B. The FOHE bypass valve is mounted on the oil control module, located at the 9 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).

4. Fault Isolation

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE AND ENGINE OIL 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 79-21-00-810-081-A ** ON A/C NOT FOR ALL

A. Do the fault isolation procedure that follows:
(1) Replace ENGINE FUEL/OIL HEAT EXCHANGER BYPASS VALVE [4112KS] AMM 79-21-09-000-801 and AMM 79-21-09-400-801.
(a) Do the test given in Para. 3.
(2) If the fault continues:
(a) Examine the W04 (4088KS), W03 (4087KS) and WC10 (4011KS) harnesses and connectors P5 (4000KS-P5) and P6 (4000KS-P6) - EEC (4000KS), interconnect J106 (4100VC)/P106 (4100VC-A), interconnect J110 (4110VC)/P110 (4110VC-A) and connector P52 (4112KS-P52) - FOHE bypass valve (4112KS), for problems which are possible between the EEC (4000KS) and the engine FOHE bypass valve (4112KS).
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 W03 HARNESS [4087KS] AMM 73-21-63-000-802 and AMM 73-21-63-400-802, or
c Replace WC10 HARNESS-CORE [4011KS] AMM 73-21-69-000-802 and AMM 73-21-69-400-802.
d Do the test given in Para. 3.
(3) If no problems are found with the harnesses, use a PLIERS - JAWED, SOFT to disconnect electrical connectors P5 (4000KS-P5) and P6 (4000KS-P6) from the EEC (4000KS), interconnect J106 (4100VC)/P106 (4100VC-A), interconnect J110 (4110VC)/P110 (4110VC-A) and connector P52 (4112KS-P52) from the engine FOHE bypass valve (4112KS).
(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 P5 (4000KS-P5) and P6 (4000KS-P6) to the EEC (4000KS), interconnect J106 (4100VC)/P106 (4100VC-A), interconnect J110 (4110VC)/P110 (4110VC-A) and connector P52 (4112KS-P52) to the engine FOHE bypass valve (4112KS).
(d) Do the test given in Para. 3.
(4) If the fault continues:
(a) Disconnect electrical connectors P5 (4000KS-P5) and P6 (4000KS-P6) from the EEC (4000KS), interconnect J106 (4100VC)/P106 (4100VC-A), interconnect J110 (4110VC)/P110 (4110VC-A) and connector P52 (4112KS-P52) from the engine FOHE bypass valve (4112KS). Use a MULTIMETER - STANDARD to test the engine FOHE bypass valve (4112KS) Linear Variable Differential Transducer (LVDT) and Torque Moteur (TM) 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: Fuel/Oil Heat Exchanger Bypass Valve LVDT circuit Channel A Connector Contacts

W04(4088KS) Harness P5 (4000KS-P5) EEC(4000KS) Connector Contacts	W04(4088KS) Harness J106 (4100VC) Connector Contacts	W03(4087KS) Harness P106 (4100VC-A) Connector Contacts	W03(4087KS) Harness J110 (4110VC) Connector Contacts	WC10(4011KS) Harness P110 (4110VC-A) Connector Contacts	WC10(4011KS) Harness P52 (4112KS-P52) FOHE bypass valve(4112KS) Connector Contacts
V	18	18	15	15	2
r	19	19	16	16	3
EE	1	1	1	1	9
MM	6	6	6	6	10
PP	7	7	7	7	11

Table 2: Fuel/Oil Heat Exchanger Bypass Valve TM circuit Channel B Connector Contacts

W03 (4087KS) Harness P6 (4000KS-P6) EEC (4000KS) Connector Contacts	W03 (4087KS) Harness J110 (4110VC) Connector Contacts	WC10 (4011KS) Harness P110 (4110VC-A) Connector Contacts	WC10 (4011KS) Harness P52 (4112KS-P52) FOHE (4112KS) Connector Contacts
B	39	39	4
d	40	40	12

(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 W03 HARNESS [4087KS] AMM 73-21-63-000-802 and AMM 73-21-63-400-802, or
3 Replace WC10 HARNESS-CORE [4011KS] AMM 73-21-69-000-802 and AMM 73-21-69-400-802.
4 Do the test given in Para. 3.
(5) If no problems are found with the harnesses or 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 79-21-00-860-070-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.

[Rev.8 from Aug 2018] 2026.04.04 04:38:36 UTC