Smiths Aerospace
Electronic Systems – Malvern
DOC NO.0134ED
MAINTENANCE MANUAL SUPPLEMENT
BOEING B737-100/200/300/400/500
28-41-04
Measure resistance from Tank Lo-Z to
Hi-Z Shield at tank wall.
Normal dry capacitance
Abnormal dry capacitance
Drain Fuel Tank.
Measure value of tank units at tank wall
(AMM 28-23-00/201)
Remove bussing plug and
measure individual tank units
(AMM 28-41-21/401)
Replace TSU
(AMM 28-41-04/401)
1
Repair fault to Hi-Z shield in tank
harness or replace
(AMM 28-41-44/401)
< 50 megohm
> 50 megohm
Remove TSU harness from tank
wall bussing connector.
(WDM 28-41-01)
Repair fault to ground in
tank harness
>50 megohm
<50 megohm
Measure resistance from Tank Lo-Z to
GND at tank wall.
Abnormal dry capacitance
Normal
Repair/Replace tank harness
(AMM 28-41-44/401)
Repair/Replace applicable tank unit
or compensator/harness
(AMM 28-41-21/401)
(AMM 28-41-44/401)
Operational Test
(AMM 28-41-04/501)
Err 4: Tank Lo-Z Line Open or Short (continued)
Figure 105 (Sheet 2)
Page 118
April 19/02
Airplanes with Smiths 2307 Model Fuel Quantity
Indicators with TSU
EFFECTIVITY
