Continuous Running of the PTU during Operation of the Cargo-Compartment Doors

TASK 29-23-00-810-807-A
Continuous Running of the PTU during Operation of the Cargo-Compartment Doors

1. Possible Causes

MANIFOLD,PTU [3015GM]
wiring
RELAY-SCCB PWR SPLY [3811GX]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 29-13-15-000-001	Removal of the Power Transfer Unit (PTU) Manifold of the Yellow Hydraulic System
AMM 29-13-15-400-001	Installation of the Power Transfer Unit (PTU) Manifold of the Yellow Hydraulic System
ASM 292301
AMM 52-30-00-860-001	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
AMM 52-30-00-860-002	Close the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump

3. Fault Confirmation
Subtask 29-23-00-710-062-A

A. Do this test:
(1) Make sure that:

the SW PARK BRK CTL (73GG) is set to OFF,
the Nose L/G is compressed,
no towing arm is installed.

(2) Operate the FWD or AFT cargo-compartment door with the Yellow electric pump AMM 52-30-00-860-001 and AMM 52-30-00-860-002.
(3) Do a check of the PTU for continuous running during the operation of the cargo-compartment door.
(4) Make sure that the the cargo-compartment door is fully opened or closed.

4. Fault Isolation
Subtask 29-23-00-810-059-C

A. If the PTU runs during the operation of the cargo-compartment door:

NOTE: Make sure that a second person operates one cargo-compartment door during all checks for 28 VDC in the subsequent procedure.

do a check for 28 VDC between:
the VALVEBLOCK, PTU (3112GL) connector A/A and the connector A/B ASM 292301.

(1) If there is 28 VDC:

replace the MANIFOLD,PTU [3015GM] AMM 29-13-15-000-001 and AMM 29-13-15-400-001.

(2) If there is no 28 VDC:

do a check for 28 VDC at the:
RELAY CTL (3811GX) connector B1 ASM 292301.

(a) If there is 28 VDC:

do a check and repair the wiring between the RELAY CTL (3811GX) connector B1 and the VALVEBLOCK, PTU (3112GL) connector A/B ASM 292301.

(b) If there is no 28 VDC:

do a check for 28 VDC at the:
RELAY CTL (3811GX) connector X1 ASM 292301.

1 If there is 28 VDC:

replace the RELAY-SCCB PWR SPLY [3811GX] .

a If the fault continues:

do a check and repair the wiring between the RELAY CTL (3811GX) connector B2 and the C/B (1801GL) ASM 292301.

2 If there is no 28 VDC:

do a check and repair the wiring of the cargo compartment door operation system.

5. Close-up
Subtask 29-23-00-710-063-A

A. Do the fault confirmation procedure as given in Para. 3. to make sure that the operation is correct.

[Rev.8 from Aug 2018] 2026.04.04 04:29:29 UTC