W DOC AIRBUS | TSM A320F

APU AUTO SHUTDOWN - NO ACCELERATION, Fuel-Control Unit Fault (131-9(A))

TASK 49-00-81-810-835-A
APU AUTO SHUTDOWN - NO ACCELERATION, Fuel-Control Unit Fault (131-9(A))

1. Possible Causes
  • NO LRU FAULT DETECTED
  • FUEL RESOLVER PRIMARY SHOWS OPEN CIRCUIT
  • FUEL RESOLVER SECONDARY SHOWS OPEN CIRCUIT
  • FUEL RESOLVER EXCITATION CIRCUIT FAILURE
  • FUEL TORQUE MOTOR SHOWS OPEN CIRCUIT
  • FUEL TORQUE MOTOR SHOWS SHORT CIRCUIT
  • blockage of the APU inlet
  • IGV ACTUATOR (8014KM)
  • APU [4005KM]
  • damage of the IGV ACTUATOR linkage and IGV assembly
  • HOT SECTION DISTRESS
  • MOTOR-STARTER [8KA]
  • aircraft BATTERIES
  • damage/leakage of the APU fuel system
  • APU internal damage
  • FUEL FILTER
  • FUEL CONTROL UNIT (P19)
  • FLOW DIVIDER (P13)
  • damage of the IGV ACTUATOR linkage and the IGV assembly
  • APU INLET PRESSURE TRANSDUCER (P22)
  • APU INLET TEMPERATURE SENSOR (P6)
  • ELECTRONIC CONTROL BOX [59KD]
  • EGT 1 and/or 2 THERMOCOUPLE
  • FUEL FILTER (8028KM)
  • FUEL CONTROL UNIT (8022KM)
  • FLOW DIVIDER (8024KM)
  • APU (4005KM).
  • APU INLET PRESSURE TRANSDUCER (8048KM)
  • APU INLET TEMPERATURE SENSOR (8010KM)
  • damage/contamination of electrical connector P19
  • aircraft wiring
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
No specific
AR
MULTIMETER - STANDARD
No specific
AR
WRENCH - RATCHET
No specific
AR
WRENCH - SOCKET
 B. Referenced Information
REFERENCE
DESIGNATION
AMM 24-38-00-210-001
Visual Inspection of the Batteries
AMM 31-36-00-740-006
Printout of the APU Hours and Cycles
AMM 31-36-00-740-011
Printout of the Manually Requested Reports
AMM 31-36-00-740-015
Printout of the Engine/APU Hours and Cycles Stored in the Flight Data Interface and Management Unit (FDIMU)
AMM 49-00-00-860-008
APU Start by External Power
AMM 49-00-00-970-001
Access to the Data Memory Module (DMM) Report (131-9(A))
AMM 49-11-11-000-004
Removal of the Power Plant (APU) (131-9(A))
AMM 49-11-11-400-004
Installation of the Power Plant (APU) (131-9(A))
AMM 49-23-14-000-001
Removal of the Sensor-APU Inlet Temperature (131-9(A))
AMM 49-23-14-400-001
Installation of the Sensor-APU Inlet Temperature (131-9(A))
AMM 49-23-51-000-004
Removal of the Inlet Guide Vane - Actuator (131-9(A))
AMM 49-23-51-400-004
Installation of the Inlet Guide Vane - Actuator (131-9(A))
AMM 49-32-11-000-003
Removal of the Fuel Control Unit (FCU) (131-9(A))
AMM 49-32-11-400-003
Installation of the Fuel Control Unit (FCU) (131-9(A))
AMM 49-32-13-000-001
Removal of Flow Divider and Solenoid Valve (131-9(A))
AMM 49-32-13-400-001
Installation of Flow Divider and Solenoid Valve (131-9(A))
AMM 49-32-41-920-001
Replacement of the Fuel Filter (131-9(A))
AMM 49-42-51-000-006
Removal of the Starter Motor (131-9(A))
AMM 49-42-51-400-006
Installation of the Starter Motor (131-9(A))
AMM 49-51-21-000-001
Removal of the Transducer - APU Inlet Pressure (131-9(A))
AMM 49-51-21-400-001
Installation of the Transducer - APU Inlet Pressure (131-9(A))
ASM 496101
ASM 496104
AMM 49-61-34-000-003
Removal of the Electronic Control Box (ECB) (131-9(A))
AMM 49-61-34-400-003
Installation of the Electronic Control Box (ECB) (131-9(A))
AMM 49-72-15-000-002
Removal of the Thermocouples (131-9(A))
AMM 49-72-15-400-003
Installation of the Thermocouples (131-9(A))
AMM 49-91-42-200-004
Inspection of the Metal Chip Detector (131-9(A))
F EGT Limit (Fuel Trim) During APU Start
3. Fault Confirmation
Subtask 49-00-81-710-158-A ** ON A/C NOT FOR ALL
A. Read-out of ECB Trouble-Shooting Data
   (1) Put the APU MASTER SW to the ON position.
   (2) Get access to the APU SHUTDOWN report.
   (3) Push the '>' adjacent to LRU DATA:
  • the MCDU menu shows
    NO LRU FAULT DETECTED
    or
    FUEL RESOLVER PRIMARY SHOWS OPEN CIRCUIT
    or
    FUEL RESOLVER SECONDARY SHOWS OPEN CIRCUIT
    or
    FUEL RESOLVER EXCITATION CIRCUIT FAILURE
    or
    FUEL TORQUE MOTOR SHOWS OPEN CIRCUIT
    or
    FUEL TORQUE MOTOR SHOWS SHORT CIRCUIT

   (4) Start the APU and apply Bleed Air for 20 seconds, minimum AMM 49-00-00-860-008.
4. Fault Isolation
Subtask 49-00-81-810-132-A ** ON A/C NOT FOR ALL
A. If an APU auto shutdown occurs during the APU operation and the APU SHUTDOWN report gives the maintenance message:

NO ACCELERATION
FCU P19 / APU FUEL SUPPLY / STARTER MOTOR 8KA

associated with Fault Code Number (FCN) 215

   (1) Do a check for a blockage of the APU inlet .
     (a) If the accumulated hours TSN/TSO are greater than 2000 hours:
  • Make sure that the APU rotates freely.
       1 If the APU rotates freely:
  • Get access to the APU DMM report AMM 49-00-00-970-001
  • Compare the value of CT5ATP (corrected EGT during MES) from the DMM page with 653 deg.C (1207.40 deg.F).
         a If EGTA exceeds 653 deg.C (1207.40 deg.F) then continue in para. 2_.
         b If EGTA does not exceed 653 deg.C (1207.40 deg.F) then continue in para (b)1_ and subsequent steps.
       2 Get access to the APU DMM report AMM 49-00-00-970-001
  • Compare the START_TIME (time of last APU start) from the DMM page versus 60 seconds.
         a If START_TIME exceeds 60 seconds (slow start time) then continue in para. 3_ .
         b If START_TIME does not exceed 60 seconds then continue in para (b)1_ and subsequent steps.
       3 Get access to the APU SHUTDOWN report 14 AMM 31-36-00-740-011:
  • Scan down and ensure that IGV position is within the normal range for APU start (10 - 22 degrees).
         a If IGV position is not in the normal range:
  • Remove the IGV ACTUATOR (8014KM) from the APU [4005KM] AMM 49-23-51-000-004.
  • Do a check for damage of the IGV ACTUATOR linkage and IGV assembly .
  • . Make sure that the IGV has a travel range of 1 -0.01 in. or +0.01 in. (25.400 -0.254 mm or +0.254 mm).
  • . Measure the force of the IGV movement.
  • If a force less than 20 lbf (8.8964 daN) is necessary to move the IGVs:
  • . Replace the IGV ACTUATOR (8014KM) AMM 49-23-51-400-004.
  • If a force more than 20 lbf (8.8964 daN) is necessary to move the IGVs or the travel range is different than 1 -0.01 in. or +0.01 in. (25.400 -0.254 mm or +0.254 mm):
  • . Replace the APU [4005KM] AMM 49-11-11-000-004 and AMM 49-11-11-400-004.
         b If IGV position is in the normal range:
  • Scan down to lines labelled "8N" and "9N", or to lines where EGTA is highest.
  • Compare APU speed (NA) and EGTA versus LCIT on the EGT Limit (Fuel Trim) during APU Start illustration.
  • . If EGTA reaches the value shown on the EGT Limit (Fuel Trim) during APU Start illustration:
  • .. High EGT is determined ( HOT SECTION DISTRESS ).
  • .. Replace the APU [4005KM] AMM 49-11-11-000-004 and AMM 49-11-11-400-004.
  • . If EGTA does not reach the value shown on the EGT Limit (Fuel Trim) during APU Start illustration then continue in Para. (b)1_ and subsequent steps.
       4 If the APU does not rotate freely:
     (b) If the accumulated hours TSN/TSO are lower than 2000 hours:
       1 Replace the MOTOR-STARTER [8KA] AMM 49-42-51-000-006 AMM 49-42-51-400-006.
       2 If the fault continues:
       3 If the fault continues:
  • Do a check for damage/leakage of the APU fuel system.
         a If there is damage/leakage in the APU fuel system:
  • Do a repair.
         b If the APU fuel system is OK:
  • Do a check for APU internal damage .
    - Do a check for contamination of the MAGNETIC-DRAIN PLUG AMM 49-91-42-200-004 .
NOTE: If the MAGNETIC-DRAIN PLUG is not contaminated, continue without starting the APU.
  • .
    - Remove the end cap of the STARTER MOTOR (8KA).
    - Use a WRENCH - SOCKET and a WRENCH - RATCHET on the shaft of the STARTER MOTOR (8KA) to turn the APU counterclockwise (in the direction of the arrow on the housing).
    - Make sure that the APU rotates freely.
         c If the APU rotates freely:
         d If the APU does not rotate freely:
Subtask 49-00-81-810-132-B ** ON A/C NOT FOR ALL
A. If an APU auto shutdown occurs during the APU operation and the APU SHUTDOWN report gives the maintenance message:

NO ACCELERATION
FCU (8022KM) / APU FUEL SUPPLY / STARTER MOTOR 8KA

associated with Fault Code Number (FCN) 215

   (1) Do a check for a blockage of the APU inlet .
     (a) If the accumulated hours TSN/TSO are greater than 2000 hours:
  • Make sure that the APU rotates freely.
       1 If the APU rotates freely:
  • Get access to the APU DMM report AMM 49-00-00-970-001
  • Compare the value of CT5ATP (corrected EGT during MES) from the DMM page with 653 deg.C (1207.40 deg.F).
         a If EGTA exceeds 653 deg.C (1207.40 deg.F) then continue in para. 2_ .
         b If EGTA does not exceed 653 deg.C (1207.40 deg.F) then continue in para (b)1_ and subsequent steps.
       2 Get access to the APU DMM report AMM 49-00-00-970-001
  • Compare the START_TIME (time of last APU start) from the DMM page versus 60 seconds.
         a If START_TIME exceeds 60 seconds (slow start time) then continue in para. 3_ .
         b If START_TIME does not exceed 60 seconds then continue in para (b)1_ and subsequent steps.
       3 Get access to the APU SHUTDOWN report 14 AMM 31-36-00-740-011:
  • Scan down and ensure that IGV position is within the normal range for APU start (10 - 22 degrees).
         a If IGV position is not in the normal range:
  • Remove the IGV ACTUATOR (8014KM) from the APU [4005KM] AMM 49-23-51-000-004.
  • Do a check for damage of the IGV ACTUATOR linkage and IGV assembly .
  • . Make sure that the IGV has a travel range of 1 -0.01 in. or +0.01 in. (25.400 -0.254 mm or +0.254 mm).
  • . Measure the force of the IGV movement.
  • If a force less than 20 lbf (8.8964 daN) is necessary to move the IGVs:
  • . Replace the IGV ACTUATOR (8014KM) AMM 49-23-51-400-004.
  • If a force more than 20 lbf (8.8964 daN) is necessary to move the IGVs or the travel range is different than 1 -0.01 in. or +0.01 in. (25.400 -0.254 mm or +0.254 mm):
  • . Replace the APU [4005KM] AMM 49-11-11-000-004 and AMM 49-11-11-400-004.
         b If IGV position is in the normal range:
  • Scan down to lines labelled "8N" and "9N", or to lines where EGTA is highest.
  • Compare APU speed (NA) and EGTA versus LCIT on the EGT Limit (Fuel Trim) during APU Start illustration.
  • . If EGTA reaches the value shown on the EGT Limit (Fuel Trim) during APU Start illustration:
  • .. High EGT is determined ( HOT SECTION DISTRESS ).
  • .. Replace the APU [4005KM] AMM 49-11-11-000-004 and AMM 49-11-11-400-004.
  • . If EGTA does not reach the value shown on the EGT Limit (Fuel Trim) during APU Start illustration then continue in Para. (b)1_ and subsequent steps.
       4 If the APU does not rotate freely:
     (b) If the accumulated hours TSN/TSO are lower than 2000 hours:
       1 Replace the MOTOR-STARTER [8KA] AMM 49-42-51-000-006 AMM 49-42-51-400-006.
       2 If the fault continues:
       3 If the fault continues:
  • Do a check for damage/leakage of the APU fuel system.
         a If there is damage/leakage in the APU fuel system:
  • Do a repair.
         b If the APU fuel system is OK:
  • Do a check for APU internal damage .
    - Do a check for contamination of the MAGNETIC-DRAIN PLUG (8077KM) AMM 49-91-42-200-004 .
NOTE: If the MAGNETIC-DRAIN PLUG is not contaminated, continue without starting the APU.
  • .
    - Remove the end cap of the STARTER MOTOR (8KA).
    - Use a WRENCH - SOCKET and a WRENCH - RATCHET on the shaft of the STARTER MOTOR (8KA) to turn the APU counterclockwise (in the direction of the arrow on the housing).
    - Make sure that the APU rotates freely.
         c If the APU rotates freely:
         d If the APU does not rotate freely:
Subtask 49-00-81-810-132-E ** ON A/C NOT FOR ALL
A. If an APU auto shutdown occurs during the APU operation and the APU SHUTDOWN report gives the maintenance message:

NO ACCELERATION
FCU (8022KM) / APU FUEL SUPPLY / STARTER MOTOR 8KA

associated with Fault Code Number (FCN) 215

   (1) Do a check for a blockage of the APU inlet .
     (a) If the accumulated hours TSN/TSO are greater than 2000 hours:
  • make sure that the APU rotates freely.
       1 If the APU rotates freely:
  • get access to the APU DMM report AMM 49-00-00-970-001
  • compare the value of CT5ATP (corrected EGT during MES) from the DMM page with 653 deg.C (1207.40 deg.F).
         a If EGTA exceeds 653 deg.C (1207.40 deg.F) then continue in para. 2_ .
         b If EGTA does not exceed 653 deg.C (1207.40 deg.F) then continue in para (b).
       2 Get access to the APU DMM report AMM 49-00-00-970-001
  • compare the START_TIME (time of last APU start) from the DMM page versus 60 seconds.
         a If START_TIME exceeds 60 seconds (slow start time) then continue in para. 3_ .
         b If START_TIME does not exceed 60 seconds then continue in para (b).
       3 Get access to the APU SHUTDOWN report 14 AMM 31-36-00-740-011:
  • scan down and ensure that IGV position is within the normal range for APU start (10 - 22 degrees).
         a If IGV position is not in the normal range:
  • remove the IGV ACTUATOR (8014KM) from the APU [4005KM] AMM 49-23-51-000-004.
  • do a check for damage of the IGV ACTUATOR linkage and IGV assembly .
  • . make sure that the IGV has a travel range of 1 -0.01 in. or +0.01 in. (25.400 -0.254 mm or +0.254 mm).
  • . measure the force of the IGV movement.
  • If a force less than 20 lbf (8.8964 daN) is necessary to move the IGVs:
  • . replace the IGV ACTUATOR (8014KM) AMM 49-23-51-400-004.
  • If a force more than 20 lbf (8.8964 daN) is necessary to move the IGVs or the travel range is different than 1 -0.01 in. or +0.01 in. (25.400 -0.254 mm or +0.254 mm):
  • . replace the APU [4005KM] AMM 49-11-11-000-004 and AMM 49-11-11-400-004.
         b If IGV position is in the normal range:
  • scan down to lines labelled "8N" and "9N", or to lines where EGTA is highest.
  • compare APU speed (NA) and EGTA versus LCIT on the EGT Limit (Fuel Trim) during APU Start illustration.
  • . If EGTA reaches the value shown on the EGT Limit (Fuel Trim) during APU Start illustration:
  • .. high EGT is determined ( HOT SECTION DISTRESS ).
  • .. replace the APU [4005KM] AMM 49-11-11-000-004 and AMM 49-11-11-400-004.
  • . If EGTA does not reach the value shown on the EGT Limit (Fuel Trim) during APU Start illustration then continue in Para. (b).
       4 If the APU does not rotate freely:
     (b) If the accumulated hours TSN/TSO are lower than 2000 hours:
       1 If the fault continues:
       2 If the fault continues:
  • do a check for damage/leakage of the APU fuel system.
         a If there is damage/leakage in the APU fuel system:
  • do a repair.
         b If the APU fuel system is OK:
  • do a check for APU internal damage .
    - do a check for contamination of the MAGNETIC-DRAIN PLUG (8077KM) AMM 49-91-42-200-004 .
NOTE: If the MAGNETIC-DRAIN PLUG is not contaminated, continue without starting the APU.
  • .
    - remove the end cap of the STARTER MOTOR (8KA).
    - use a WRENCH - SOCKET and a WRENCH - RATCHET on the shaft of the STARTER MOTOR (8KA) to turn the APU counterclockwise (in the direction of the arrow on the housing).
    - make sure that the APU rotates freely.
         c If the APU rotates freely:
         d If the APU does not rotate freely:
Subtask 49-00-81-810-112-A ** ON A/C NOT FOR ALL
B. If an APU auto shutdown occurs during the APU operation and the APU SHUTDOWN report gives the maintenance message:

NO ACCELERATION
FUEL CONTROL UNIT P19

associated with Fault Code Numbers (FCN) 76 OR 77

  • do a check for damage/contamination of electrical connector P19 of the FUEL CONTROL UNIT (P19)
   (1) If the electrical connector P19 is damaged/contaminated:
  • do a repair/cleaning.
   (2) If the electrical connector is OK:
  • use a MULTIMETER - STANDARD to do a resistance check across
    pin 2 and pin 3 (PRIMARY FCU RESOLVER); required value between 50 Ohms and 95 Ohms
    and
    pin 2/pin 3 and pin 1 (PRIMARY FCU RESOLVER); required value > 40 MOhms
    and
    pin 10/pin 11 and pin 12 (SECONDARY FCU RESOLVER); required value between 65 Ohms and 105 Ohms
    and
    pin 10/pin 11 and pin 1 (SECONDARY FCU RESOLVER); required value > 40 MOhms
    of the FUEL CONTROL UNIT (P19).
     (a) If the resistance values are out of the specified limits:
     (b) If the resistance values are in the specified limits:
  • do a check and repair of the aircraft wiring from
    the ECB (59KD) AB/A10,A11 to FUEL CONTROL UNIT (P19) P19/2,3 (PRIMARY FCU RESOLVER)
    and
    the ECB (59KD) AB/H10,B5,B6 to FUEL CONTROL UNIT (P19) P19/12,10,11 (SECONDARY FCU RESOLVER) ASM 496104:
       1 If the fault continues:
Subtask 49-00-81-810-122-A ** ON A/C NOT FOR ALL
C. If an APU auto shutdown occurs during the APU operation and the APU SHUTDOWN report gives the maintenance message:

NO ACCELERATION
FUEL CONTROL UNIT P19

associated with Fault Code Numbers (FCN) 105, 106, 107 or 108

  • do a check for damage/contamination of electrical connector P19 of the FUEL CONTROL UNIT (P19)
   (1) If the electrical connector P19 is damaged/contaminated:
  • do a repair/cleaning.
   (2) If the electrical connector is OK:
  • use a MULTIMETER - STANDARD to do a resistance check across
    pin 6 and pin 7
    of the FUEL CONTROL UNIT (P19).
     (a) If the resistance value is not between 31 Ohms and 41 Ohms:
     (b) If the resistance value is in the specified limit:
  • do a check and repair of the aircraft wiring from
    the ECB (59KD) AB/H11,G7 to the FUEL CONTROL UNIT (P19) P19/6,7 ASM 496101.
       1 If the fault continues:
Subtask 49-00-81-810-112-B ** ON A/C NOT FOR ALL
D. If an APU auto shutdown occurs during the APU operation and the APU SHUTDOWN report gives the maintenance message:

NO ACCELERATION
FUEL CONTROL UNIT (8022KM)

associated with Fault Code Numbers (FCN) 76 OR 77

  • do a check for damage/contamination of electrical connector P19 of the FUEL CONTROL UNIT (8022KM)
   (1) If the electrical connector P19 is damaged/contaminated:
  • do a repair/cleaning.
   (2) If the electrical connector is OK:
  • use a MULTIMETER - STANDARD to do a resistance check across
    pin 2 and pin 3 (PRIMARY FCU RESOLVER); required value between 50 Ohms and 95 Ohms
    and
    pin 2/pin 3 and pin 1 (PRIMARY FCU RESOLVER); required value > 40 MOhms
    and
    pin 10/pin 11 and pin 12 (SECONDARY FCU RESOLVER); required value between 65 Ohms and 105 Ohms
    and
    pin 10/pin 11 and pin 1 (SECONDARY FCU RESOLVER); required value > 40 MOhms
    of the FUEL CONTROL UNIT (8022KM).
     (a) If the resistance values are out of the specified limits:
     (b) If the resistance values are in the specified limits:
  • do a check and repair of the aircraft wiring from
    the ECB (59KD) AB/A10,A11 to FUEL CONTROL UNIT (P19) P19/2,3 (PRIMARY FCU RESOLVER)
    and
    the ECB (59KD) AB/H10,B5,B6 to FUEL CONTROL UNIT (P19) P19/12,10,11 (SECONDARY FCU RESOLVER) ASM 496104.
       1 If the fault continues:
Subtask 49-00-81-810-122-B ** ON A/C NOT FOR ALL
E. If an APU auto shutdown occurs during the APU operation and the APU SHUTDOWN report gives the maintenance message:

NO ACCELERATION
FUEL CONTROL UNIT (8022KM)

associated with Fault Code Numbers (FCN) 105, 106, 107 or 108

  • do a check for damage/contamination of electrical connector P19 of the FUEL CONTROL UNIT (8022KM)
   (1) If the electrical connector P19 is damaged/contaminated:
  • do a repair/cleaning.
   (2) If the electrical connector is OK:
  • use a MULTIMETER - STANDARD to do a resistance check across
    pin 6 and pin 7
    of the FUEL CONTROL UNIT (8022KM)
     (a) If the resistance value is not between 31 Ohms and 41 Ohms:
     (b) If the resistance value is in the specified limit:
  • do a check and repair of the aircraft wiring from
    the ECB (59KD) AB/H11,G7 to the FUEL CONTROL UNIT (8022KM) P19/6,7 ASM 496101.
       1 If the fault continues:
Subtask 49-00-81-810-178-C ** ON A/C NOT FOR ALL
F. If an APU auto shutdown occurs during the APU operation and the APU SHUTDOWN report gives the maintenance message:

NO ACCELERATION
FUEL CONTROL UNIT (8022KM)/ECB (59KD)

associated with Fault Code Numbers (FCN) 75

  • do a check for damage/contamination of electrical connector P19 of the FUEL CONTROL UNIT (8022KM)
   (1) If the electrical connector P19 is damaged/contaminated:
  • do a repair/cleaning.
   (2) If the electrical connector is OK:
  • use a MULTIMETER - STANDARD to do a resistance check across
    pin 2 and pin 3 (FCU RESOLVER EXCITATION); required value between 50 Ohms and 95 Ohms of the FUEL CONTROL UNIT (8022KM).
     (a) If the resistance values are out of the specified limits:
     (b) If the resistance values are in the specified limit:
  • do a check and repair of the aircraft wiring from
    the ECB (59KD) AB/A10,A11 to the FUEL CONTROL UNIT (8022KM) P19/2,3 (FCU RESOLVER EXCITATION) ASM 496104.
       1 If the fault continues:
Subtask 49-00-81-710-159-A ** ON A/C NOT FOR ALL
G. Do the operational test of the APU AMM 49-00-00-860-008.
[Rev.8 from Aug 2018] 2026.04.04 04:34:34 UTC
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