P2 Synthesized in Disagreement with ADIRUx

TASK 73-21-00-810-894-A
P2 Synthesized in Disagreement with ADIRUx

1. Possible Causes

HARNESS-FAN, WF02 [4218KS]
HARNESS-FAN, WF01 [4217KS]
ADIRU-1 [1FP1]
ADIRU-2 [1FP2]
aircraft wirings
[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 34-12-34-000-001	Removal of the ADIRU
AMM 34-12-34-400-001	Installation of the ADIRU
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 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 732524
AWM 732525
AWM 732533
AWM 732534
EEC Wiring Harnesses
Pylon Junction Box Connections
ARINC Output Bus Wiring Schematic
ARINC Output Bus Wiring Schematic

3. Fault Confirmation
Subtask 73-21-00-710-147-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 A and channel B have detected that the engine inlet air pressure (P2) and Air Data and Inertial Reference Unit (ADIRU) circuits do not agree. The ADIRU 1 and ADIRU 2 are located in the avionics compartment. The engine inlet air pressure (P2) signal is synthesized within the EEC. 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).

(3) 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.
(4) 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 73-21-00-810-166-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 WF02 (4218KS) and WF01 (4217KS) harnesses, connectors P1 (4000KS-P1), P2 (4000KS-P2) - EEC (4000KS), and connectors P402 (402VC-A), P403 (403VC-A) - pylon junction box, for problems which are possible between the EEC (4000KS) and the pylon junction box.
(a) Inspect for harnesses 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 the HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802, or
2 Replace the HARNESS-FAN, WF01 [4217KS] AMM 73-21-61-000-802 and AMM 73-21-61-400-802.
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 P1 (4000KS-P1), P2 (4000KS-P2) from the EEC (4000KS) and connectors P402 (402VC-A), P403 (403VC-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), P2 (4000KS-P2) to the EEC (4000KS) and connectors P402 (402VC-A), P403 (403VC-A) to the pylon junction box.
(d) Do the test given in Para. 3.
(4) If the fault continues:
(a) Disconnect the electrical connectors P1 (4000KS-P1), P2 (4000KS-P2) from the EEC (4000KS) and connectors P402 (402VC-A), P403 (403VC-A) from the pylon junction box. Use a MULTIMETER - STANDARD to test the ADIRU 1 and ADIRU 2 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: ADIRU 1 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
X	10
t	25

Table 2: ADIRU 2 Channel B Connector Contacts

WF01 (4217KS) Harness P2 (4000KS-P2) EEC (4000KS) Connector Contacts	WF01 (4217KS) Harness P403 (403VC-A) Pylon Junction Box Connector Contacts
X	10
t	25

(b) If a problem is found with the harnesses or connectors:
1 Replace the HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802, or
2 Replace the HARNESS-FAN, WF01 [4217KS] AMM 73-21-61-000-802 and AMM 73-21-61-400-802.
3 Do the test given in Para. 3.
(5) If no problems are found with the harnesses or the fault continues:
(a) Remove ADIRU-1 [1FP1] and ADIRU-2 [1FP2] AMM 34-12-34-000-001.
(b) Disconnect electrical connectors P402 (402VC-A) and P403 (403VC-A) from the pylon junction box. Use a MULTIMETER - STANDARD to test the ADIRU 1 and ADIRU 2 circuits in the harnesses. Refer to Table 3 and Table 4 for fault on ENG 1 and Table 5 and 6 for fault on ENG 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 3: ADIRU 1 / ENG 1 Channel A Connector Contacts

ADIRU-1 (1FP1) Connector Contacts	WF02 (4218KS) Harness P402 (402VC1-A) Pylon Junction Box Connector Contacts
12B	10
12D	25

Table 4: ADIRU 2 / ENG 1 Channel B Connector Contacts

ADIRU-2 (1FP2) Connector Contacts	WF01 (4217KS) Harness P403 (403VC1-A) Pylon Junction Box Connector Contacts
12B	10
12D	25

Table 5: ADIRU 1 / ENG 2 Channel A Connector Contacts

ADIRU-1 (1FP1) Connector Contacts	WF02 (4218KS) Harness P402 (402VC1-A) Pylon Junction Box Connector Contacts
14B	10
14D	25

Table 6: ADIRU 2 / ENG 2 Channel B Connector Contacts

ADIRU-2 (1FP2) Connector Contacts	WF01 (4217KS) Harness P403 (403VC1-A) Pylon Junction Box Connector Contacts
14B	10
14D	25

For fault on ENG 1: refer to AWM 732525 and AWM 732533.
For fault on ENG 2: refer to AWM 732524 and AWM 732534.

2 Install ADIRU-1 [1FP1] and ADIRU-2 [1FP2] AMM 34-12-34-400-001.
3 Reconnect all connectors.
4 Do the test given in Para. 3.
(6) If the fault continues:
(a) Replace the ADIRU-1 [1FP1] AMM 34-12-34-000-001 and AMM 34-12-34-400-001.
(b) Do the test given in Para. 3.
(7) If the fault continues:
(a) Replace the ADIRU-2 [1FP2] AMM 34-12-34-000-001 and AMM 34-12-34-400-001.
(b) Do the test given in Para. 3.
(8) 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 73-21-00-860-086-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 fan cowl doors AMM 71-13-00-410-802.

[Rev.8 from Aug 2018] 2026.04.04 04:40:52 UTC