Engine Position Failure

TASK 73-00-00-810-938-A
Engine Position Failure

1. Possible Causes

HARNESS-FAN, WF01 [4217KS]
HARNESS-FAN, WF02 [4218KS]
EIU-1 [1KS1]
EIU-2 [1KS2]
[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 24-41-00-861-002	Energize the Aircraft Electrical Circuits from the External Power
AMM 24-41-00-862-002	De-energize the Aircraft Electrical Circuits Supplied from the External Power
AMM 70-70-00-910-803	SPOP 6 - Cleaning of the Contact Points and Wiring Harnesses
AMM 71-13-00-010-802	Opening of the Fan Cowl Doors
AMM 71-13-00-410-802	Closing of the Fan Cowl Doors
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 73-21-61-000-802	Removal of the Electronic Engine Control (EEC) Wiring Harness (WF01)
AMM 73-21-61-400-802	Installation of the Electronic Engine Control (EEC) Wiring Harness (WF01)
AMM 73-21-62-000-802	Removal of the EEC Wiring Harness (WF02)
AMM 73-21-62-400-802	Installation of the EEC Wiring Harness (WF02)
AWM 732503
AWM 732504
AMM 73-25-34-000-802	Removal of the Engine Interface Unit (EIU)
AMM 73-25-34-400-802	Installation of the Engine Interface Unit (EIU)
AMM 73-25-34-860-805	Check and Uploading of the EIU Software
EEC Wiring Harnesses
Pylon Junction Box Connections
Engine Position Channel B Wiring Schematic
Pylon Junction Box Channel A Wiring Schematic
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
AWM 732503
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
AWM 732504

3. Fault Confirmation
Subtask 73-00-00-710-378-A ** ON A/C NOT FOR ALL

A. Energize the FADEC of the engine that has a fault report.
(1) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
(2) On the ENG section of maintenance panel 50VU:
(a) Release the FADEC GND PWR/1(2) pushbutton switch (the ON legend comes on).

NOTE: After the FADEC is energized, wait ten seconds before you start the test. If you do not wait ten seconds, the interactive mode stops the EEC self-test and this can cause spurious faults.

(3) On Multipurpose Control and Display Unit (MCDU) screen, check if the fault is displayed on ground scanning report .

NOTE: The EEC has detected the circuits for the engine position discrete on channel B and Engine Interface Unit (EIU) on channel A do not agree. The engine position discretes are configured using hardwired jumpers in the pylon wire harness. The EIU is located in the avionics compartment. The EEC is located on the fan case at the 2 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) 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.
(5) 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 73-00-00-810-292-A ** ON A/C NOT FOR ALL

A. If there is confirmation of the fault:
(1) Open the fan cowl doors AMM 71-13-00-010-802.
(2) Examine the WF01 (4217KS) and WF02 (4218KS) harnesses, connectors P2 (4000KS-P2) and P1 (4000KS-P1) - EEC (4000KS) and connectors P407 (407VC-A) and P402 (402VC-A) - Pylon junction box, for problems which are possible between the EEC (4000KS) and the pylon junction box.
(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 HARNESS-FAN, WF01 [4217KS] AMM 73-21-61-000-802 and AMM 73-21-61-400-802, or
2 Replace HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802.
3 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 the electrical connectors P2 (4000KS-P2) and P1 (4000KS-P1) from the EEC (4000KS) and connectors P407 (407VC-A) and P402 (402VC-A) from the pylon junction box.
(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 the electrical connectors P2 (4000KS-P2) and P1 (4000KS-P1) to the EEC (4000KS) and connectors P407 (407VC-A) and P402 (402VC-A) to the pylon junction box.
(d) Do the test given in Para. 3.
(4) If the fault continues:
(a) Disconnect the electrical connectors P2 (4000KS-P2) and P1 (4000KS-P1) from the EEC (4000KS) and connectors P407 (407VC-A) and P402 (402VC-A) from the pylon junction box. Use a MULTIMETER - STANDARD to test the engine position discrete and EIU circuits in the harness. 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: Engine Position Channnel B Connector Contacts

WF01 (4217KS) Harness P2(4000KS-P2) EEC (4000KS) Connector Contacts	WF01(4217KS) Harness P407 (407VC-A) Pylon Junction Box Connector Contacts
MM	19
LL	20
PP	8

Table 2: EIU Channel A Connector Contacts

WF02 (4218KS) Harness P1(4000KS-P1) EEC (4000KS) Connector Contacts	WF02(4218KS) Harness P402 (402VC-A) Pylon Junction Box Connector Contacts
GG	4
HH	12

(b) If a problem is found with the harnesses or connectors:
1 Replace HARNESS-FAN, WF01 [4217KS] AMM 73-21-61-000-802 and AMM 73-21-61-400-802, or
2 Replace HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802.
3 Do the test given in Para. 3.
(5) If no problems are found with the WF01 (4217KS) harness, check the circuit for correct jumper configuration in the pylon harness from (407VC). Refer to Table 3.
(a) Use the pylon harness engine position configuration chart below to continuity check the jumper circuits in the pylon harness for proper configuration. Refer to Table 3.
(b) Check for wire-to-wire shorts and shorts to ground in the jumper circuits.

Table 3: Engine Position Configuration Selection

Pylon jumper circuit connection, continuity from (407VC) pins 19 and 8	Pylon jumper circuit connection, continuity from (407VC) pins 20 and 8	Configured Engine Location
pins 19 and 8 Open	pins 20 and 8 Open	Illegal
pins 19 and 8 Jumpered	pins 20 and 8 Open	Left Engine
pins 19 and 8 Open	pins 20 and 8 Jumpered	Right Engine
pins 19 and 8 Jumpered	pins 20 and 8 Jumpered	Illegal

(c) If a problem is found with the engine position jumper configuration in the pylon harness, use the aircraft Wiring Diagram Manual(WDM) to repair or replace the pylon harness.
1 FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
refer to AWM 732503.
2 FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
refer to AWM 732504.
3 Do the test given in Para. 3.
(6) If the fault continues, check the EIU position AMM 73-25-34-860-805.
(a) If the fault is on ENG1:
1 On MCDU, for EIU1, check the status of the discrete input for ENG1.
2 If the status is not correct, repair wiring from pin 3A and 3E on connector AA AWM 732503.
(b) If the fault is on ENG2:
1 On MCDU, for EIU2, check the status of the discrete input for ENG2.
2 If the status is not correct, repair wiring from pin 3E and 4B on connector AA AWM 732504.
(c) If the status is correct:
1 Replace EIU-1 [1KS1] or EIU-2 [1KS2] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
2 Do the test given in Para. 3.
(7) 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 73-00-00-860-215-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.
(2) Close the fan cowl doors AMM 71-13-00-410-802.
(3) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.

[Rev.8 from Aug 2018] 2026.04.04 04:41:18 UTC