EGT TCPLE Rake 1 Fault (131-9(A))

TASK 49-70-00-810-817-A
EGT TCPLE Rake 1 Fault (131-9(A))

1. Possible Causes

EGT1 SENSOR SHOWS OUT OF RANGE LOW
EGT1 SENSOR DISAGREES WITH EGT2 SENSOR > 66C
damage/contamination of the electrical connections
EGT 1 THERMOCOUPLE
aircraft wiring
EGT TCPLE RAKE (8057KM1)
ELECTRONIC CONTROL BOX [59KD]
EGT 2 THERMOCOUPLE
PRIMARY FUEL-NOZZLE and MANIFOLD
SECONDARY FUEL-NOZZLE and MANIFOLD
EGT TCPLE RAKE (8057KM2)
PRIMARY FUEL-NOZZLE and MANIFOLD (8020KM)
SECONDARY FUEL-NOZZLE and MANIFOLD (8021KM)

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	MULTIMETER - STANDARD

B. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 49-70-00-810-818-A	EGT TCPLE Rake 2 Fault (131-9(A))
AMM 49-00-00-860-008	APU Start by External Power
AMM 49-31-41-000-003	Removal of the Primary and Secondary Fuel-Nozzle (131-9(A))
AMM 49-31-41-400-003	Installation of the Primary and Secondary Fuel- Nozzle (131-9(A))
AMM 49-31-42-000-004	Removal of the Primary and Secondary Fuel-Manifold (131-9(A))
AMM 49-31-42-400-006	Installation of the Primary and Secondary Fuel-Manifold (131-9(A))
ASM 496101
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))

3. Fault Confirmation
Subtask 49-70-00-710-080-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 LAST LEG/PREVIOUS LEG report.
(3) Push the '>'-key adjacent to the related CFDS failure message.
(4) If the MCDU menu shows:
EGT1 SENSOR SHOWS OUT OF RANGE LOW

do the Fault Confirmation that follows:

(a) Get access to the APU GND SCANNING menu.
(5) If the MCDU menu shows:
EGT1 SENSOR DISAGREES WITH EGT2 SENSOR > 66C

do the Fault Confirmation that follows:

(a) Start the APU and apply Electrical Load and Bleed Air AMM 49-00-00-860-008.
(b) Get access to the APU GND SCANNING menu.

4. Fault Isolation
Subtask 49-70-00-810-065-A ** ON A/C NOT FOR ALL

A. If the APU GND SCANNING menu gives the maintenance message:

EGT TCPLE RAKE 1

associated with Fault Code Number (FCN) 42

do a check for damage/contamination of the electrical connections of the EGT 1 THERMOCOUPLE.

(1) If the electrical connection of the EGT 1 THERMOCOUPLE is damaged/contaminated:

do a repair/cleaning.

(2) If the electrical connections of the EGT 1 THERMOCOUPLE is OK:

use a MULTIMETER - STANDARD to do a resistance check across the terminals chromel and alumel of the EGT 1 THERMOCOUPLE.

(a) If the resistance is >20 Ohms:

replace the EGT 1 THERMOCOUPLE AMM 49-72-15-000-002 and AMM 49-72-15-400-003.

(b) If the resistance is < 20 Ohms:

do a check of the aircraft wiring from the ECB (59KD) AB/A6,A7 to the EGT 1 THERMOCOUPLE terminals chromel/alumel ASM 496101.

1 If the fault continues:

replace the ECB (59KD) AMM 49-61-34-000-003 and AMM 49-61-34-400-003.

Subtask 49-70-00-810-066-A ** ON A/C NOT FOR ALL

B. If the APU GND SCANNING menu gives the maintenance message:

EGT TCPLE RAKE 1

associated with Fault Code Number (FCN) 43

do a check for damage/contamination of the electrical connections of the EGT 1 THERMOCOUPLE.

(1) If the electrical connection of the EGT 1 THERMOCOUPLE is damaged/contaminated:

do a repair/cleaning.

(2) If the electrical connections of the EGT 1 THERMOCOUPLE is OK:

use a MULTIMETER - STANDARD to do a resistance check across the terminals:
chromel and alumel of the EGT 1 THERMOCOUPLE; required value < 20 Ohms
and
chromel and grounded EGT 1 mount flange; required value > 100 kOhms
and
alumel and grounded EGT 1 mount flange; required value > 100 kOhms.

(a) If the resistance values are out of the specified limits:

replace the EGT 1 THERMOCOUPLE AMM 49-72-15-000-002 and AMM 49-72-15-400-003.

(b) If the resistance values are in the specified limits:

do a check of the aircraft wiring from the ECB (59KD) AB/A6,A7 to the EGT 1 THERMOCOUPLE terminals chromel/alumel ASM 496101.

1 If the fault continues:

replace the ELECTRONIC CONTROL BOX [59KD] AMM 49-61-34-000-003 and AMM 49-61-34-400-003.

2 If the fault continues:

do a check for of the EGT 2 THERMOCOUPLE (Ref. TSM TASK 49-70-00-810-818)

3 If the fault continues:

replace the PRIMARY FUEL-NOZZLE and MANIFOLD ( AMM 49-31-41-000-003 and AMM 49-31-41-400-003) and the SECONDARY FUEL-NOZZLE and MANIFOLD ( AMM 49-31-42-000-004 and AMM 49-31-42-400-006).

Subtask 49-70-00-810-065-B ** ON A/C NOT FOR ALL

C. If the APU GND SCANNING menu gives the maintenance message:

EGT TCPLE RAKE (8057KM1)

associated with Fault Code Number (FCN) 42

do a check for damage/contamination of the electrical connections of the EGT TCPLE RAKE (8057KM1)

(1) If the electrical connection of the EGT TCPLE RAKE (8057KM1) is damaged/contaminated:

do a repair/cleaning.

(2) If the electrical connections of the EGT TCPLE RAKE (8057KM1) are OK:

use a MULTIMETER - STANDARD to do a resistance check across the terminals chromel and alumel of the EGT TCPLE RAKE (8057KM1).

(a) If the resistance is >20 Ohms:

replace the EGT TCPLE RAKE (8057KM1) AMM 49-72-15-000-002 and AMM 49-72-15-400-003.

(b) If the resistance is < 20 Ohms:

do a check of the aircraft wiring from the ECB (59KD) AB/A6,A7 to the EGT TCPLE RAKE (8057KM1) terminals chromel/alumel ASM 496101.

1 If the fault continues:

replace the ECB (59KD) AMM 49-61-34-000-003 and AMM 49-61-34-400-003.

Subtask 49-70-00-810-066-B ** ON A/C NOT FOR ALL

D. If the APU GND SCANNING menu gives the maintenance message:

EGT TCPLE RAKE (8057KM1)

associated with Fault Code Number (FCN) 43

do a check for damage/contamination of the electrical connections of the EGT TCPLE RAKE (8057KM1).

(1) If the electrical connection of the EGT TCPLE RAKE (8057KM1) is damaged/contaminated:

do a repair/cleaning.

(2) If the electrical connections of the EGT TCPLE RAKE (8057KM1) is OK:

use a MULTIMETER - STANDARD to do a resistance check across the terminals:
chromel and alumel of the EGT 1 THERMOCOUPLE; required value < 20 Ohms
and
chromel and grounded EGT 1 mount flange; required value > 100 kOhms
and
alumel and grounded EGT 1 mount flange; required value > 100 kOhms.

(a) If the resistance values are out of the specified limits:

replace the EGT TCPLE RAKE (8057KM1) AMM 49-72-15-000-002 and AMM 49-72-15-400-003.

(b) If the resistance values are in the specified limits:

do a check of the aircraft wiring from the ECB (59KD) AB/A6,A7 to the EGT TCPLE RAKE (8057KM1) terminals chromel/alumel ASM 496101.

1 If the fault continues:

replace the ELECTRONIC CONTROL BOX [59KD] AMM 49-61-34-000-003 and AMM 49-61-34-400-003.

2 If the fault continues:

do a check for of the EGT TCPLE RAKE (8057KM2) (Ref. TSM TASK 49-70-00-810-818)

3 If the fault continues:

replace the PRIMARY FUEL-NOZZLE and MANIFOLD (8020KM) ( AMM 49-31-41-000-003 and AMM 49-31-41-400-003) and the SECONDARY FUEL-NOZZLE and MANIFOLD (8021KM) ( AMM 49-31-42-000-004 and AMM 49-31-42-400-006).

Subtask 49-70-00-710-081-A ** ON A/C NOT FOR ALL

E. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:34:41 UTC