Continuous Load-Compressor Surge or Load-Compressor Reverse Flow (APS 3200)

TASK 49-00-00-810-947-A
Continuous Load-Compressor Surge or Load-Compressor Reverse Flow (APS 3200)

1. Possible Causes

COMPRESSOR DISCHARGE-PRESSURE SENSOR (8039KM)
BLD CTL VLV (8051KM)
INLET PRESSURE/TEMPERATURE SENSOR (8013KM)
wiring
INLET GUIDE-VANE ACTUATOR (8014KM)
ELECTRONIC CONTROL BOX [59KD]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 49-00-00-810-937-A	No APU Bleed-Air Pressure, Low or Fluctuating APU Bleed-Air Pressure (with AIDS support) (APS 3200)
ESPM 2052210
ESPM 2053210
ESPM 205321A
AMM 49-00-00-710-008	Operational Test of the APU
AMM 49-20-00-290-001	APU Power Plant Borescope Inspection (APS 3200)
AMM 49-23-17-000-001	Removal of the Inlet Pressure/Temperature Sensor (APS 3200)
AMM 49-23-17-400-001	Installation of the Inlet Pressure/Temperature Sensor (APS 3200)
AMM 49-23-51-000-003	Removal of the Inlet Guide Vane Actuator (APS 3200)
AMM 49-23-51-400-003	Installation of the Inlet Guide Vane Actuator (APS 3200)
AMM 49-51-19-000-002	Removal of the Sensor - Compressor Discharge Pressure (APS 3200)
AMM 49-51-19-400-002	Installation of the Sensor - Compressor Discharge Pressure (APS 3200)
AMM 49-51-53-000-001	Removal of the Bleed Control Valve (APS 3200)
AMM 49-51-53-400-001	Installation of the Bleed Control Valve (APS 3200)
ASM 496102
AMM 49-61-34-000-002	Removal of the Electronic Control Box (ECB) (APS 3200)
AMM 49-61-34-400-002	Installation of the Electronic Control Box (ECB) (APS 3200)

3. Fault Confirmation
Subtask 49-00-00-710-320-A ** ON A/C NOT FOR ALL

A. Do the operational test of the APU AMM 49-00-00-710-008.

4. Fault Isolation
Subtask 49-00-00-810-307-B ** ON A/C NOT FOR ALL

A. If the APU Last Leg Report gives the maintenance message:

BLD FLOW XDCR (8039KM) / BLD CTL VLV (8051KM)
Fault Code Number: 169

NOTE: Do a check and make sure that the orifices and the lines which are connected to the compressor discharge-pressure sensor are not clogged.
Clean the orifices and the lines if necessary.
Make sure that the Load Control Valve sense line is correctly installed and torqued.

NOTE: Do a check of the IGV Actuator guide pin for correct installation. If the pin is disengaged, replace the pin or carry out the APIC VSB 4500001-49-84.

replace the COMPRESSOR DISCHARGE-PRESSURE SENSOR (8039KM) AMM 49-51-19-000-002 and AMM 49-51-19-400-002.

(1) If the fault continues:

replace the BLD CTL VLV (8051KM) AMM 49-51-53-000-001 and AMM 49-51-53-400-001.

(a) If the fault continues:

replace the INLET PRESSURE/TEMPERATURE SENSOR (8013KM) AMM 49-23-17-000-001 and AMM 49-23-17-400-001.

1 If the fault continues:

do a check of the wiring from the ECB (59KD) AB/A1, A4, B2, B3, A2, A3 to the COMPRESSOR DISCHARGE-PRESSURE SENSOR P24/1, 2, 3, 4, 5, 6 ASM 496102 ESPM 2052210 ESPM 2053210 ESPM 205321A.

a If the fault continues:

do a check of the wiring from the ECB (59KD) AB/A1, A4, C8, C9, D3, E6 to the INLET PRESSURE/TEMPERATURE SENSOR (8013KM) P22/1, 2, 3, 4, 6, 5 ASM 496102 ESPM 2052210 ESPM 2053210 ESPM 205321A.

b If the fault continues:

replace the INLET GUIDE-VANE ACTUATOR (8014KM) AMM 49-23-51-000-003 and AMM 49-23-51-400-003.

2 If the fault continues:

replace the ELECTRONIC CONTROL BOX [59KD] AMM 49-61-34-000-002 and AMM 49-61-34-400-002.

3 If the fault continues:

do a check for air flow blockage by external parts or damaged plenum baffle of the air inlet.

4 If the fault continues:

do the borescope inspection of the load compressor AMM 49-20-00-290-001.

5 If the fault continues:

do the TSM procedure (Ref. TSM TASK 49-00-00-810-937).

Subtask 49-00-00-710-321-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:34:27 UTC