Disagreement of the Position Switches of the Crossbleed Valve

TASK 36-12-00-810-803-A
Disagreement of the Position Switches of the Crossbleed Valve

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 36-11-00-740-001	BITE Test of the BMC 1(2)
AMM 36-11-34-000-001	Removal of the BMC
AMM 36-11-34-400-001	Installation of the BMC
ASM 361201
AMM 36-12-52-000-002	Removal of the Crossbleed Valve Actuator
AMM 36-12-52-400-002	Installation of the Crossbleed Valve Actuator
AMM 49-00-00-860-005	APU Start by External Power
AMM 49-00-00-860-006	APU Shutdown by External Power
AMM 49-00-00-860-008	APU Start by External Power
AMM 49-00-00-860-009	APU Shutdown by External Power (131-9(A))

3. Fault Confirmation
Subtask 36-12-00-710-054-B ** ON A/C NOT FOR ALL

A. Test
(1) Start the APU AMM 49-00-00-860-005.
(2) Do the operational test of both BMCs AMM 36-11-00-740-001.
(3) Stop the APU AMM 49-00-00-860-006.

Subtask 36-12-00-710-054-C ** ON A/C NOT FOR ALL

A. Test
(1) Start the APU AMM 49-00-00-860-008.
(2) Do the operational test of both BMCs AMM 36-11-00-740-001.
(3) Stop the APU AMM 49-00-00-860-009.

4. Fault Isolation
Subtask 36-12-00-810-055-A ** ON A/C NOT FOR ALL

A. If both BMCs give the maintenance message X FEED-V 6HV OR CKT:

(1) If the fault continues:

do a check and repair the wiring between:
the BMC-1, BMC-2 (1HA1/2) AB/1A,2A and the CROSSBLEED VALVE [6HV] A/F,D ASM 361201,
do a check and repair the wiring between:
the CROSSBLEED VALVE [6HV] A/N and ground ASM 361201.

(2) If the fault continues:

do a check and repair the wiring between:
the BMC-1, BMC-2 (1HA1/2) connectors AB/3A,4A and the CROSSBLEED-VALVE SELECTOR SWITCH (3HV) connectors A/2,4 ASM 361201,
do a check and repair the wiring between:
the CROSSBLEED-VALVE SELECTOR SWITCH (3HV) connector A/1 and ground ASM 361201.

Subtask 36-12-00-810-056-A ** ON A/C NOT FOR ALL

B. If only one BMC gives the maintenance message X FEED VALVE 6HV OR CKT:

(1) If the fault continues:

do a check and repair the wiring between:
the related BMC connectors AB/1A,2A,3A,4A and the first terminal block ASM 361201.

Subtask 36-12-00-710-055-A ** ON A/C NOT FOR ALL

C. Do the test as given in Para. 3. to make sure that the operation is correct (no maintenance message shown).

[Rev.8 from Aug 2018] 2026.04.04 04:34:00 UTC