TRA Disagreement Failure

TASK 76-11-00-810-828-A
TRA Disagreement Failure

1. Possible Causes

CTL UNIT-THROTTLE, ENG 1 [8KS1]
CTL UNIT-THROTTLE, ENG 2 [8KS2]
HARNESS-FAN, WF01 [4217KS]
HARNESS-FAN, WF02 [4218KS]
[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 73-21-00-710-806	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 73-21-61-000-802	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 732541
AWM 732542
AWM 732543
AWM 732544
AMM 76-11-51-000-802	Removal of the Throttle Control Unit
AMM 76-11-51-400-802	Installation of the Throttle Control Unit
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
Pylon Junction Box Connections
Throttle Resolver Angle Channel A Wiring Schematic
Throttle Resolver Angle Channel B Wiring Schematic

3. Fault Confirmation
Subtask 76-11-00-710-093-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 that the Throttle Resolver Angle (TRA) circuits for the Throttle Control Unit (TCU) do not agree between channel A and channel B. The TCU is located in the cockpit.

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 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.
(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 76-11-00-810-079-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 CTL UNIT-THROTTLE, ENG 1 [8KS1] or CTL UNIT-THROTTLE, ENG 2 [8KS2] AMM 76-11-51-000-802 and AMM 76-11-51-400-802.
(a) Do the test given in Para. 3.
(3) If the fault continues:
(a) Examine the WF01 (4217KS) and WF02 (4218KS) harnesses, connectors P1 (4000KS-P1) and P2 (4000KS-P2) - EEC (4000KS) and connectors P406 (406VC-A) and P407 (407VC-A) - Pylon junction box, for problems which are possible between the EEC (4000KS) and the pylon junction box.
1 Inspect for harnesses 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 HARNESS-FAN, WF01 [4217KS] AMM 73-21-61-000-802 and AMM 73-21-61-400-802, or
b Replace HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802.
c Do the test given in Para. 3.
(4) If no problems are found with the harnesses or the fault continues, use a PLIERS - JAWED, SOFT to disconnect the electrical connectors P1 (4000KS-P1) and P2 (4000KS-P2) from the EEC (4000KS) and connectors P406 (406VC-A) and P407 (407VC-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 connector face AMM 70-70-00-910-803.
(c) Reconnect the electrical connectors P1 (4000KS-P1) and P2 (4000KS-P2) to the EEC (4000KS) and connectors P406 (406VC-A) and P407 (407VC-A) to the pylon junction box.
(d) Do the test given in Para. 3.
(5) If the fault continues:
(a) Disconnect the electrical connectors P1 (4000KS-P1) and P2 (4000KS-P2) from the EEC (4000KS) and connectors P406 (406VC-A) and P407 (407VC-A) from the pylon junction box. Use a MULTIMETER - STANDARD to test the TRA 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: TRA Channel A Circuit Connector Contacts

WF02 (4218KS) Harness P1 (4000KS-P1) EEC (4000KS) Connector Contacts	WF02 (4218KS) Harness P406 (406VC-A) Pylon Junction Box Connector Contacts
CC	3
BB	12
AA	13
z	14
g	15
F	5

Table 2: TRA Channel B Circuit Connector Contacts

WF01 (4217KS) Harness P2 (4000KS-P2) EEC (4000KS) Connector Contacts	WF01 (4217KS) Harness P407 (407VC-A) Pylon Junction Box Connector Contacts
CC	3
BB	12
AA	13
z	14
g	15
F	5

(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.
(6) If no problems are found with the harnesses or the fault continues:
(a) Do a check of the aircraft wiring containing the TCU (8KS) to the pylon junction box (406VC) and (407VC).
- For fault on ENG 1, refer to AWM 732541 and AWM 732543.
- For fault on ENG 2, refer to AWM 732542 and AWM 732544.
1 Refer to Table 3 and Table 4. Look for:

Wire-to-wire shorts
Shorts to ground
Continuity (less than 5 ohms resistance).

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

Table 3: Aircraft Wiring Channel A Circuit Connector Contacts

(406VC-A) Pylon Junction Box Connector Contacts	TCU (8KS) Connector C
3	B
12	A
13	C
14	D
15	E
5	F

Table 4: Aircraft Wiring Channel A Circuit Connector Contacts

(407VC-A) Pylon Junction Box Connector Contacts	TCU (8KS) Connector D
3	B
12	A
13	C
14	D
15	E
5	F

2 Repair wiring as necessary
3 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 76-11-00-860-051-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 04:37:29 UTC