W DOC AIRBUS | TSM A320F

The EGT indication fluctuates while other parameters are stable on Engine 1

TASK 77-20-00-810-830-A
The EGT indication fluctuates while other parameters are stable on Engine 1

1. Possible Causes
  • T495 probes
  • Main Electrical Junction Box
  • CJ13 Harness
  • ECU [4000KS]
  • J13 Harness
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 71-00-00-710-006
Minimum Idle Check
AMM 73-21-50-000-005
Removal of the CJ13 Harness
AMM 73-21-50-000-012
Removal of the J13 Harness
AMM 73-21-50-000-029
Removal of the CJ13 Harness
AMM 73-21-50-000-046
Removal of the HJ13 Harness for SAC Engines
AMM 73-21-50-210-001
Visual Inspection of the Wiring Harness
AMM 73-21-50-210-002
Visual Inspection of the Wiring Harnesses
AMM 73-21-50-400-005
Installation of the CJ13 Harness
AMM 73-21-50-400-012
Installation of the J13 Harness
AMM 73-21-50-400-029
Installation of the CJ13 Harness
AMM 73-21-50-400-046
Installation of the HJ13 Harness for SAC Engines
AMM 73-21-60-000-001
Removal of the Electronic Control Unit (ECU)
AMM 73-21-60-400-001
Installation of the Electronic Control Unit (ECU)
AMM 73-21-60-740-001
Read the CLASS 3 REPORT
AMM 73-21-60-740-007
Correct Time Limited Faults (Non Asterisked) of the Engine Scheduled Maintenance Report
AMM 73-21-60-740-026
Read the CLASS 3 REPORT
AMM 73-21-60-740-027
Read the Specific Data Report
AMM 73-21-60-740-028
Correct Faults of the Engine Scheduled Maintenance Report (SMR)
AMM 77-21-10-000-002
Removal of the Main Junction Box
AMM 77-21-10-000-025
Removal of the Main Junction Box
AMM 77-21-10-200-001
Inspection/Check of the T495 Thermocouple Wiring Harness
AMM 77-21-10-200-002
Inspection/Check of the T495 Thermocouple Wiring Harness
AMM 77-21-10-400-002
Installation of the Main Junction Box
AMM 77-21-10-400-025
Installation of the Main Junction Box
3. Fault Confirmation
Subtask 77-20-00-710-094-A ** ON A/C NOT FOR ALL
A. Test
   (1) Not applicable.
NOTE: Most likely cause for an EGT fluctuation (while other parameters are stable) is oxidation deposit on the CJ13 harness connector onto the junction box receptacle. Therefore, as a first attempt to fix the fault, the connector/receptacle (CJ13 harness connector and Main Junction Box receptacle) must be cleaned per procedure here below.
4. Fault Isolation
Subtask 77-20-00-810-072-A ** ON A/C NOT FOR ALL
A. If EGT fluctuations have been reported and other engine parameters were stable:
  • Do a check of the Post Flight Report (PFR), of the Schedule Maintenance Report (SMR) or Class 3 Report AMM 73-21-60-740-007, and of the FADEC Last Leg Report for a T495 SNSR failure message.
   (1) If message is found:
  • Do the related troubleshooting procedure.
   (2) If nothing is found:
  • Disconnect the CJ13 harness from the T495 main junction box (located in the left core compartment), and visually examine the T495 junction box receptacle and the CJ13 harness connector for damaged pins or contamination AMM 73-21-50-210-001. Clean the connector and the receptacle using a bristle brush and stoddart solvant (CP 2011) or white spirit (CP 2010).
     (a) If damage is found:
  • replace or repair as necessary.
     (b) If nothing is found:
  • Disconnect the J13 harness from the ECU (4000KS), and visually examine the ECU receptacle and the harness connector for damaged pins or contamination AMM 73-21-50-210-001.
       1 If damage is found:
  • repair or replace as required.
       2 If nothing is found, continue the troubleshooting as follows.
   (3) Do a visual inspection of the J13 and CJ13 harnesses connectors for looseness.
     (a) If a connector is found loose:
  • do a cleaning of the connector and the receptacle using a bristle brush and stoddart solvant (CP 2011) or white spirit (CP 2010) AMM 73-21-50-210-001
     (b) If nothing is found:
  • do a visual inspection of the T495 probes lead assemblies and check for damage.
       1 If damage is found:
  • repair or replace damaged hardware as required.
   (4) If the fault continues during the subsequent flight:
  • Do an electrical resistance test through the Main Electrical Junction Box between:
    . pins A and B (1 to 10 ohms)
    . pin A and the ground (> 20 megohms)
     (a) If the resistances are out of the specified limits:
  • Do an electrical resistance test of the T495 thermocouple wiring harness (probes lead assemblies and extension leads assemblies) AMM 77-21-10-200-001
     (b) If the resistances are in the specified limits:
   (5) If the fault continues during the subsequent flight:
   (6) If the fault continues during the subsequent flight:
   (7) If the fault continues during the subsequent flight:
Subtask 77-20-00-810-072-C ** ON A/C NOT FOR ALL
A. If EGT fluctuations have been reported and other engine parameters were stable:
  • Do a check of the Post Flight Report (PFR), of the Schedule Maintenance Report (SMR) or Class 3 Report AMM 73-21-60-740-001 and AMM 73-21-60-740-028 , and of the FADEC Last Leg Report for a T495 SNSR failure message.
   (1) If message is found:
  • Do the related troubleshooting procedure.
   (2) If nothing is found:
  • Disconnect the CJ13 harness from the T495 main junction box (located in the left core compartment), and visually examine the T495 junction box receptacle and the CJ13 harness connector for damaged pins or contamination AMM 73-21-50-210-001. Clean the connector and the receptacle using a bristle brush and stoddart solvant (CP 2011) or white spirit (CP 2010).
     (a) If damage is found:
  • replace or repair as necessary.
     (b) If nothing is found:
  • Disconnect the J13 harness from the ECU (4000KS), and visually examine the ECU receptacle and the harness connector for damaged pins or contamination AMM 73-21-50-210-001.
       1 If damage is found:
  • repair or replace as required.
       2 If nothing is found, continue the troubleshooting as follows.
   (3) Do a visual inspection of the J13 and CJ13 harnesses connectors for looseness.
     (a) If a connector is found loose:
  • do a cleaning of the connector and the receptacle using a bristle brush and stoddart solvant (CP 2011) or white spirit (CP 2010) AMM 73-21-50-210-001
     (b) If nothing is found:
  • do a visual inspection of the T495 probes lead assemblies and check for damage.
       1 If damage is found:
  • repair or replace damaged hardware as required.
   (4) If the fault continues during the subsequent flight:
  • Do an electrical resistance test through the Main Electrical Junction Box between:
    . pins A and B (1 to 10 ohms)
    . pin A and the ground (> 20 megohms)
     (a) If the resistances are out of the specified limits:
  • Do an electrical resistance test of the T495 thermocouple wiring harness (probes lead assemblies and extension leads assemblies) AMM 77-21-10-200-001
     (b) If the resistances are in the specified limits:
   (5) If the fault continues during the subsequent flight:
   (6) If the fault continues during the subsequent flight:
   (7) If the fault continues during the subsequent flight:
Subtask 77-20-00-810-072-E ** ON A/C NOT FOR ALL
A. If EGT fluctuations have been reported and other engine parameters were stable:
   (1) If message is found:
  • Do the related troubleshooting procedure.
   (2) If nothing is found:
  • Disconnect the CJ13 harness from the T495 main junction box (located in the left core compartment), and visually examine the T495 junction box receptacle and the CJ13 harness connector for damaged pins or contamination AMM 73-21-50-210-002. Clean the connector and the receptacle using a bristle brush and stoddart solvant (CP 2011) or white spirit (CP 2010).
     (a) If damage is found:
  • replace or repair as necessary.
     (b) If nothing is found:
  • Disconnect the J13 harness from the ECU (4000KS), and visually examine the ECU receptacle and the harness connector for damaged pins or contamination AMM 73-21-50-210-002.
       1 If damage is found:
  • repair or replace as required.
       2 If nothing is found, continue the troubleshooting as follows.
   (3) Do a visual inspection of the J13 and CJ13 harnesses connectors for looseness.
     (a) If a connector is found loose:
  • do a cleaning of the connector and the receptacle using a bristle brush and stoddart solvant (CP 2011) or white spirit (CP 2010) AMM 73-21-50-210-002
     (b) If nothing is found:
  • do a visual inspection of the T495 probes lead assemblies and check for damage.
       1 If damage is found:
  • repair or replace damaged hardware as required.
   (4) If the fault continues during the subsequent flight:
  • Do an electrical resistance test through the Main Electrical Junction Box between:
    . pins A and B (1 to 10 ohms)
    . pin A and the ground (> 20 megohms)
     (a) If the resistances are out of the specified limits:
  • Do an electrical resistance test of the T495 thermocouple wiring harness (probes lead assemblies and extension leads assemblies) AMM 77-21-10-200-002
     (b) If the resistances are in the specified limits:
   (5) If the fault continues during the subsequent flight:
   (6) If the fault continues during the subsequent flight:
   (7) If the fault continues during the subsequent flight:
5. Close-up
Subtask 77-20-00-710-095-A ** ON A/C NOT FOR ALL
A. Do a minimum idle check AMM 71-00-00-710-006.
   (1) Repeat the fault isolation procedure, if the fault continues.
[Rev.8 from Aug 2018] 2026.04.04 04:40:59 UTC
"AVIABRAIN" 2025