DOC AIRBUS | TSM A320FPAMB in Disagreement with ADIRUx or PAMB in Range Failed
TASK 73-21-00-810-A01-A
PAMB in Disagreement with ADIRUx or PAMB in Range Failed
1. Possible Causes
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Fault Confirmation
Subtask 73-21-00-710-256-A ** ON A/C NOT FOR ALL
Subtask 73-21-00-860-103-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:36:43 UTC
PAMB in Disagreement with ADIRUx or PAMB in Range Failed
1. Possible Causes
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 |
| 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 34-13-00-740-007 | GROUND SCANNING of the ADR |
| 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 732525 | |
| AWM 732533 | |
EEC Wiring HarnessesSubtask 73-21-00-710-256-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 MCDU screen, check if the fault is displayed on ground scanning report.
(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(1) Shutdown the engine AMM 71-00-00-860-814.
(2) On 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 Ambient Air Pressure (PAMB) sensor and the Air Data and Inertial Reference Unit (ADIRU) 1 and 2 circuits do not agree. The ADIRU 1 and 2 are located in the avionics compartment. The PAMB sensor is internal to the EEC and senses ambient air pressure through a port in the EEC housing which is reported to channel A of the EEC. The EEC is located on the fan case at the 2 o'clock position.
(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). - 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).
(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.
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 73-21-00-810-305-A ** ON A/C NOT FOR ALL A. If there is confirmation of the fault:
(1) Do a ground scanning of the Air Data Reference (ADR) AMM 34-13-00-740-007.
(a) If ADIRU1 (1FP1) ADR BUS j and ADIRU2 (1FP2) ADR BUS j messages come on, troubleshoot them first.
1 Do the test given in Para. 3.
(b) If these messages do not come on or if fault continues, go to next step.
(2) Open the fan cowl doors AMM 71-13-00-010-802.
(3) Examine the WF02 (4218KS) and WF01 (4217KS) harnesses, connectors P1 (4000KS-P1) and P2 (4000KS-P2) - EEC (4000KS) and connectors P402 (402VC-A) and 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.
1 Replace HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802, or
2 Replace 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.
(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 P402 (402VC-A) and 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) and P2 (4000KS-P2) to the EEC (4000KS) and connectors P402 (402VC-A) and P403 (403VC-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 P402 (402VC-A) and P403 (403VC-A) from the pylon junction box. Use a MULTIMETER - STANDARD to test the ADIRU1 and ADIRU2 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).
Table 2: ADIRU Channel B Connector Contacts
(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.
(6) If no problems are found with the harnesses or the fault continues:
(a) Do a check of the aircraft wiring from the ADIRU 1 (1FP1) and ADIRU 2 (1FP2) to the pylon junction box. Refer to AWM 732525 and AWM 732533.
1 Look for:
(b) Do the test given in Para. 3.
(7) If the fault continues:
(a) Replace
(b) Do the test given in Para. 3.
5. Close-up(1) Do a ground scanning of the Air Data Reference (ADR) AMM 34-13-00-740-007.
(a) If ADIRU1 (1FP1) ADR BUS j and ADIRU2 (1FP2) ADR BUS j messages come on, troubleshoot them first.
1 Do the test given in Para. 3.
(b) If these messages do not come on or if fault continues, go to next step.
(2) Open the fan cowl doors AMM 71-13-00-010-802.
(3) Examine the WF02 (4218KS) and WF01 (4217KS) harnesses, connectors P1 (4000KS-P1) and P2 (4000KS-P2) - EEC (4000KS) and connectors P402 (402VC-A) and 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 HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802, or
2 Replace 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.
(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 P402 (402VC-A) and 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) and P2 (4000KS-P2) to the EEC (4000KS) and connectors P402 (402VC-A) and P403 (403VC-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 P402 (402VC-A) and P403 (403VC-A) from the pylon junction box. Use a MULTIMETER - STANDARD to test the ADIRU1 and ADIRU2 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 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 |
| 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 |
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.
(6) If no problems are found with the harnesses or the fault continues:
(a) Do a check of the aircraft wiring from the ADIRU 1 (1FP1) and ADIRU 2 (1FP2) to the pylon junction box. Refer to AWM 732525 and AWM 732533.
1 Look for:
- Wire-to-wire shorts
- Shorts to ground
- Continuity (less than 5 ohms resistance).
(b) Do the test given in Para. 3.
(7) If the fault continues:
(a) Replace
(b) Do the test given in Para. 3.
Subtask 73-21-00-860-103-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.
(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.