CRANK/NORM/IGN Selector Fault on EIU-1

TASK 73-25-00-810-A24-A
CRANK/NORM/IGN Selector Fault on EIU-1

1. Possible Causes

EIU-1 [1KS1]
SEL SW-ENG/MODE/CRANK/AUTO IGN/IGN [6KS]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AWM 732509
AMM 73-25-34-000-802	Removal of the Engine Interface Unit (EIU)
AMM 73-25-34-400-802	Installation of the Engine Interface Unit (EIU)
AMM 73-25-34-710-802	Operational Test of the Engine Interface Unit (EIU) with the Centralized Fault Display System (CFDS)
AMM 73-25-34-860-806	Engine Interface Unit (EIU) DISCRETE INPUTS Menu Data Status

3. Fault Confirmation
Subtask 73-25-00-710-461-A ** ON A/C NOT FOR ALL

A. Do the test as follows:

WARNING: MAKE SURE THAT NO PERSON DOES WORK ON THE ENGINE WHEN THE IGNITION SELECTOR SWITCH IS IN THE "IGN" POSITION. THE IGNITION SYSTEM USES HIGH ENERGY WHICH IS DANGEROUS. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY OR DEATH CAN OCCUR.

(1) On ENG panel 115VU, make sure that the ENG/MASTER 1 control switch (3KC) is in OFF position.
(2) Put the ENG/MODE/CRANK/AUTO IGN/IGN selector switch (6KS) in CRANK position.
(3) Do the operational test of the Engine Interface Unit (EIU) with the Centralized Fault Display System (CFDS) to confirm this fault AMM 73-25-34-710-802.
(a) Return to CFDS menu.
(4) Put the ENG/MODE/CRANK/AUTO IGN/IGN selector switch (6KS) successively in IGN and NORM positions then repeat twice step (2) and (3).
(5) Record the selector switch position(s) (IGN/NORM/CRANK) that confirm(s) the fault.

4. Fault Isolation
Subtask 73-25-00-810-293-A ** ON A/C NOT FOR ALL

A. If there is confirmation of the fault:

(1) On ENG panel 115VU, make sure that the ENG/MASTER 1 control switch (3KC) is in OFF position.
(2) Put the ENG/MODE/CRANK/AUTO IGN/IGN selector switch (6KS) successively in IGN, NORM and CRANK positions.
(a) Check the status of the EIU-1 discrete input for IGN SEL/NORM SEL/CRANK SEL AMM 73-25-34-860-806.
(b) The status of the selected position must be equal to 1.
(c) The status of the two other not selected positions must be equal to 0.
(3) If all statuses are correct:
(a) Replace EIU-1 [1KS1] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
(b) Do the test given in Para. 3.
(4) If at least one status is not correct, remove EIU-1 [1KS1] AMM 73-25-34-000-802.
(a) Remove SEL SW-ENG/MODE/CRANK/AUTO IGN/IGN [6KS] .
(b) Check wiring of all faulty lines between EIU-1 (1KS1) connector AA and ENG/MODE/CRANK/AUTO IGN/IGN selector switch (6KS) AWM 732509.
1 Refer to Table 1 and look for:

Wire-to-wire shorts
Shorts to ground
Continuity (less than 5 ohms resistance).

NOTE: A short to ground is found when the resistance is less than 100 000 (100K) ohms.

Table 1: Selector Switch/EIU Connector Contacts

Selector Switch (6KS) Connector Pins	EIU-1 (1KS1) Connector AA Pins
2	1C
3	1A
4	1B
1 at the ground

2 If wiring is not OK, repair/replace wiring AWM 732509.
3 If wiring is OK, replace SEL SW-ENG/MODE/CRANK/AUTO IGN/IGN [6KS] AWM 732509.
4 Do the test given in Para. 3.

5. Close-up
Subtask 73-25-00-860-070-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.
(1) Put the ENG/MODE/CRANK/AUTO IGN/IGN selector switch (6KS) in NORM position if necessary.

[Rev.8 from Aug 2018] 2026.04.04 04:36:28 UTC