W DOC AIRBUS | TSM A320F

Loss of the T25 Sensor Signal through the Channel B on Engine 1

TASK 73-20-00-810-855-A
Loss of the T25 Sensor Signal through the Channel B on Engine 1

1. Possible Causes
  • harness J12
  • ECU [4000KS]
  • harness CJ12R
  • T25 temperature sensor
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
No specific
AR
BRUSH - BRISTLED
 B. Consumable Materials
REFERENCE
DESIGNATION
(Material No.CP2011)
stoddard solvent
 C. Referenced Information
REFERENCE
DESIGNATION
AMM 73-21-20-000-001
Removal of the T25 Temperature Sensor
AMM 73-21-20-000-002
Removal of the T25 Temperature Sensor
AMM 73-21-20-400-001
Installation of the T25 Temperature Sensor
AMM 73-21-20-400-002
Installation of the T25 Temperature Sensor
AMM 73-21-50-000-004
Removal of the CJ12R Harness
AMM 73-21-50-000-011
Removal of the J12 Harness
AMM 73-21-50-000-028
Removal of the CJ12R Harness for SAC Engines
AMM 73-21-50-000-045
Removal of the HJ12 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 73-21-50-400-004
Installation of the CJ12R Harness
AMM 73-21-50-400-011
Installation of the J12 Harness
AMM 73-21-50-400-028
Installation of the CJ12R Harness for SAC Engines
AMM 73-21-50-400-045
Installation of the HJ12 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)
ASM 732518
AMM 73-29-00-710-040
Operational Test of the FADEC on the ground (with Engine Motoring)
3. Fault Confirmation
Subtask 73-20-00-710-126-A ** ON A/C NOT FOR ALL
A. Do the operational test of the FADEC 1B on the ground (with engine non motoring) AMM 73-29-00-710-040.
4. Fault Isolation
Subtask 73-20-00-810-105-A ** ON A/C NOT FOR ALL
A. If the test gives the maintenance message T25 SENS, J12, ECU:
  • do a check for open or short to ground of the harness J12 between the ECU (4000KS) and the 6 o'clock junction box, between the 6 o'clock junction box and the T25 temperature sensor pins J12/19, 37, 38 to pins J12/1, 2, 3 ASM 732518.
   (1) If the wiring is not correct:
  • repair the above wiring.
   (2) If the wiring is correct:
  • disconnect the harness J12 from the ECU (4000KS).
  • do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
  • if you find damage, repair or replace as required.
  • clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-001.
  • do a check of the ECU cable resistance between:
    . pins 37 and 38 (160 to 250 Ohms)
    . pins 37 and 19 (> 10 Megohms)
    . pin 37 and the ground (> 10 Megohms).
     (a) If the resistance values are in the specified limits:
     (b) If the resistance values are out of the specified limits:
  • disconnect the harness CJ12 at the 6 o'clock junction box.
  • do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
  • if you find damage, repair or replace as required.
  • clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-001.
  • do a check of the resistance of the cable CJ12R between:
    . pins 15 and 16 (160 to 250 Ohms)
    . pins 15 and 5 (> 10 Megohms)
    . pin 15 and the ground (> 10 Megohms).
       1 If the resistance values are in the specified limits:
       2 If the resistance values are out of the specified limits:
  • disconnect the harness CJ12R at the T25 temperature sensor.
  • do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
  • if you find damage, repair or replace as required.
  • clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-001.
  • do a check of the T25 sensor resistance between:
    . pins 1 and 2 (160 to 250 Ohms)
    . pin 1 and the ground (> 10 Megohms).
         a If the resistance values are in the specified limits:
         b If the resistance values are out of the specified limits:
Subtask 73-20-00-810-105-B ** ON A/C NOT FOR ALL
A. If the test gives the maintenance message T25 SNSR, J12, ECU:
  • do a check for open or short to ground of the harness J12 between the ECU (4000KS) and the 6 o'clock junction box, between the 6 o'clock junction box and the T25 temperature sensor pins J12/19, 37, 38 to pins J12/1, 2, 3 ASM 732518.
   (1) If the wiring is not correct:
  • repair the above wiring.
   (2) If the wiring is correct:
  • disconnect the harness J12 from the ECU (4000KS).
  • do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
  • if you find damage, repair or replace as required.
  • clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-001.
  • do a check of the ECU cable resistance between:
    . pins 37 and 38 (160 to 250 Ohms)
    . pins 37 and 19 (> 10 Megohms)
    . pin 37 and the ground (> 10 Megohms).
     (a) If the resistance values are in the specified limits:
     (b) If the resistance values are out of the specified limits:
  • disconnect the harness CJ12 at the 6 o'clock junction box.
  • do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
  • if you find damage, repair or replace as required.
  • clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-001.
  • do a check of the resistance of the cable CJ12R between:
    . pins 15 and 16 (160 to 250 Ohms)
    . pins 15 and 5 (> 10 Megohms)
    . pin 15 and the ground (> 10 Megohms).
       1 If the resistance values are in the specified limits:
       2 If the resistance values are out of the specified limits:
  • disconnect the harness CJ12R at the T25 temperature sensor.
  • do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
  • if you find damage, repair or replace as required.
  • clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-001.
  • do a check of the T25 sensor resistance between:
    .pins 1 and 2 (160 to 250 Ohms)
    . pin 1 and the ground (> 10 Megohms).
         a If the resistance values are in the specified limits:
         b If the resistance values are out of the specified limits:
Subtask 73-20-00-810-105-C ** ON A/C NOT FOR ALL
A. If the test gives the maintenance message T25 SNSR, J12, ECU:
  • do a check for open or short to ground of the harness J12 between the ECU (4000KS) and the 6 o'clock junction box, between the 6 o'clock junction box and the T25 temperature sensor pins J12/19, 37, 38 to pins J12/1, 2, 3 ASM 732518.
   (1) If the wiring is not correct:
  • repair the above wiring.
   (2) If the wiring is correct:
  • disconnect the harness J12 from the ECU (4000KS).
  • do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
  • if you find damage, repair or replace as required.
  • clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-002.
  • do a check of the ECU cable resistance between:
    . pins 37 and 38 (160 to 250 Ohms)
    . pins 37 and 19 (> 10 Megohms)
    . pin 37 and the ground (> 10 Megohms).
     (a) If the resistance values are in the specified limits:
     (b) If the resistance values are out of the specified limits:
  • disconnect the harness CJ12 at the 6 o'clock junction box.
  • do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
  • if you find damage, repair or replace as required.
  • clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-002.
  • do a check of the resistance of the cable CJ12R between:
    . pins 15 and 16 (160 to 250 Ohms)
    . pins 15 and 5 (> 10 Megohms)
    . pin 15 and the ground (> 10 Megohms).
       1 If the resistance values are in the specified limits:
       2 If the resistance values are out of the specified limits:
  • disconnect the harness CJ12R at the T25 temperature sensor.
  • do a visual inspection of the harness connector and receptacle. Look for contamination or oxidation or pins that have damage.
  • if you find damage, repair or replace as required.
  • clean the connector and receptacle with a BRUSH - BRISTLED and stoddard solvent (Material No.CP2011) AMM 73-21-50-210-002.
  • do a check of the T25 sensor resistance between:
    .pins 1 and 2 (160 to 250 Ohms)
    . pin 1 and the ground (> 10 Megohms).
         a If the resistance values are in the specified limits:
         b If the resistance values are out of the specified limits:
Subtask 73-20-00-710-127-A ** ON A/C NOT FOR ALL
B. Do the test given in Para. 3.A.
[Rev.8 from Aug 2018] 2026.04.04 04:41:03 UTC
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