DOC AIRBUS | TSM A320FFailure of the T2.5 Sensor on Engine 1
1. Possible Causes
NOTE: This task is to troubleshoot the Clear Language Message (CLM) T2.5 SENS/HC/EEC1. The fault codes or
fault acronyms listed in the fault confirmation section below will help you to focus on the correct cause of
this CLM.
· harness from the EEC connector (4000KS-J10) to the T2.5 sensor (4026KS)
· T2.5 sensor (4026KS)
· EEC ( 4000KS )
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
Ref. AMM 24-41-00-861-002 Energize the Aircraft Electrical Circuits from the External Power
Ref. AMM 24-41-00-862-002 De-energize the Aircraft Electrical Circuits Supplied from the External
Power
Ref. AMM 31-60-00-860-002 EIS Stop Procedure
Ref. AMM 70-23-15-912-010 Connection of Electrical Connectors
Ref. AMM 71-00-00-710-018 Discontinued Start, Restart and Shutdown Procedures
Ref. AMM 71-00-00-710-043 Normal Engine Automatic Start Procedure
Ref. AMM 71-00-00-710-047 Normal Engine Manual Start Procedure
Ref. AMM 71-13-00-410-010 Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
Ref. AMM 71-50-00-210-010 Wire Harness Visual Inspection - All Power Plant Electrical Cables
Ref. AMM 72-32-03-300-011 Fan Frame T2.5CM Repair - VRS1596
Ref. AMM 73-22-34-000-010 Removal of the Electronic Engine Control (EEC)
Ref. AMM 73-22-34-400-010 Installation of the Electronic Engine Control (EEC)
Ref. ASM 73-25-18
Ref. AMM 78-30-00-440-012 Re-activation of the Thrust Reverser Hydraulic Control Unit (HCU) after
Ground Maintenance
Ref. AMM 78-32-00-410-010 Closing of the Thrust Reverser Halves
70-00-00-03-13 STANDARD PRACTICES - ENGINE - GENERAL - TASK SUPPORTING
DATA
REFERENCE DESIGNATION
Failure of the T2.5 Sensor on Engine 1(2) SHEET 1
Figure 73(IAE)-22-00-991-00900-A / SHEET 1/1 - Failure of the T2.5 Sensor on Engine 1(2) not
printed, as per printing preferences
3. Fault Confirmation
Subtask 73-22-00-860-114-A
A. Job Set-Up
(1) Energize the aircraft electrical circuits
Ref. AMM 24-41-00-861-002 .
(2) On the ENG section of the maintenace panel 50VU, select FADEC GND PWR 1 pushbutton switch to
the ON position.
Subtask 73-22-00-710-144-B
B. Identify the Test for Fault Confirmation
NOTE: Troubleshooting can start immediately without doing the fault confirmation if this CLM was shown
in multiple flight or ground legs.
(1) Do the CFDS message decoding and read the scheduled maintenance report to identify the fault
acronym related to the CLM (Ref. TSM 70-00-00-03) .
(2) If the readout gives the fault acronym T25L in FADEC 1B, do the steps in Para 3.C for fault
confirmation (engine idle run to confirm the fault).
(a) If the test gives the fault acronym T25L or there are two or more occurrences in fault history,
continue with fault isolation Para 4.A.
(b) If the test does not give the fault acronym T25L and there is no history of faults, send the engine
back to service.
Subtask 73-22-00-710-242-B
C. Do a test for fault acronym T25L.
(1) On the ENG section of the maintenace panel 50VU, select FADEC GND PWR 1 pushbutton switch to
the ON position.
NOTE: This step resets the FADEC memory.
(2) Push the INIT mode key. The INIT page comes into view.
(3) Start the engine 1 by the normal engine automatic start procedure Ref. AMM 71-00-00-710-043 or
the normal engine manual start procedure Ref. AMM 71-00-00-710-047 .
NOTE: You must operate the engine for a minimum of three minutes. If not, the LAST LEG REPORT
will not be erased and the fault will not be kept again in the EEC LAST LEG REPORT.
(4) Do the shutdown of the engine 1 by the discontinued start, restart and shutdown procedure Ref.
AMM 71-00-00-710-018 .
(5) Read the LAST LEG REPORT and the scheduled maintenance report of the FADEC 1B menu on the
MCDU (Ref. TSM 70-00-00-03) .
(a) Make a record of the fault message.
(b) Make a record of the channel FADEC 1B which found the fault.
(c) Do the CFDS message decoding and read the flight data and ground data to identify the fault
acronym.
4. Fault Isolation
(Ref. Fig. Failure of the T2.5 Sensor on Engine 1(2) SHEET 1)
Subtask 73-22-00-810-101-B
A. Fault Isolation for Fault Acronym T25L
· The T2.5 sensor signal is out of range. This is caused by an open, short to ground, or has a wire to wire
short in this circuit.
NOTE: After each step that is done during this procedure, you can do the steps in Para 3. to make sure
the fault is corrected.
NOTE: Disconnection and connection of the electrical connectors can correct this fault.
NOTE: The fault acronym T25L can be found only in channel B.
(1) If the fault was found, do the steps that follow:
(a) Visually examine the harness from the EEC connector (4000KS-J10) to the T2.5 sensor
(4026KS) Ref. AMM 71-50-00-210-010 .
1 Look for harness damage.
2 Look for loose or damaged connectors.
3 Look for loose or damaged backshells.
NOTE: Loose backshells must be disassembled and examined for internal wiring chafing.
4 If a problem is found with the harness, repair or replace as necessary.
(b) If no problems were found with the harness, disconnect the harness from T2.5 sensor (4026KS)
Ref. AMM 72-32-03-300-011 .
(c) Do this electrical check of the T2.5 sensor (4026KS).
1 Make sure that CR and AL studs are not shorted to ground.
2 Make sure that CR and AL studs are not shorted to each other.
3 Make sure the resistance between the CR stud to the AL stud is between 0.4 and 1.8 ohms.
4 If a problem is found, remove and replace the T2.5 sensor (4026KS) Ref.
AMM 72-32-03-300-011 .
(d) If no problems were found, disconnect electrical connector (4000KS-J10) from the EEC (4000KS)
Ref. AMM 71-50-00-210-010 . Examine the male and female parts of the connection.
1 Examine pins and sockets (contacts) for alignment and damage.
2 Look for contacts pushed rearward into the connector face.
3 Look for ovalized sockets in the connector.
NOTE: This can be done by inserting a harness connector pin into each socket. You must
feel friction when you insert and remove the pin.
4 Repair as necessary.
(e) Do this electrical check of the harness. Look for:
1 Wire to wire shorts and shorts to ground.
· Wire to wire short check: measure resistance between wires. If resistance is below
100000 (100K) ohms, then the wires are shorted and must be repaired.
· Wire to ground short check: measure resistance between wire and engine metal or
ground. If resistance is below 100000 (100K) ohms, then the wire is shorted to ground and
must be repaired.
2 Continuity.
· Continuity check: measure resistance between ends of same wire. If resistance is more
than 10 ohms, then the wire must be repaired.
NOTE: An incorrectly wired harness can cause this problem. When you test these circuits,
make sure the contacts are installed in the correct positions in each connector as
specified in the wiring diagram.
T2.5 Sensor Circuit (Channel B only)
T2.5 Sensor (4026KS) EEC (4000KS)
(4026KS-A) (4000KS-J10)
Contacts Contacts
CR W
AL V
3 If a problem is found with the harness, repair or replace as necessary Ref. ASM 73-25-18.
(f) Install all removed connectors Ref. AMM 70-23-15-912-010 and Ref. AMM 72-32-03-300-011 .
(g) Do the test for this fault, listed in Para 3. for fault confirmation.
1 If the test does not give the fault acronym T25L, send the engine back to service.
2 If the test gives the fault acronym T25L, remove and replace the T2.5 sensor (4026KS) Ref.
AMM 72-32-03-300-011 .
3 If this fault continues, remove and replace the EEC ( 4000KS ) Ref.
AMM 73-22-34-000-010 and Ref. AMM 73-22-34-400-010 .
5. Close-up
Subtask 73-22-00-860-115-A
A. Put the aircraft back to its initial configuration.
(1) Make sure that the thrust reverser halves are closed Ref. AMM 78-32-00-410-010 .
(2) Activate the thrust reverser HCU Ref. AMM 78-30-00-440-012 .
(3) Make sure that the fan cowls 437AL and 438AR are closed Ref. AMM 71-13-00-410-010 .
(4) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
Ref. AMM 31-60-00-860-002 .
(5) On the panel 50VU, push the ENG FADEC GND PWR 1 pushbutton switch.
(6) De-energize the aircraft electrical circuits
Ref. AMM 24-41-00-862-002 .
(7) Remove the warning notice(s). [Rev.6 from Feb 2017] 2026.04.04 04:36:16 UTC