Smiths Aerospace
Electronic Systems – Malvern
DOC NO.0134ED
MAINTENANCE MANUAL SUPPLEMENT
BOEING B737-100/200/300/400/500
28-41-04
Digital Calibration Trim Unit (DCTU) Installation
A. Access
(1) Location Zone
(a) 101
Control Cabin Left
(b) 102
Control Cabin Right
B. Procedure
(1) Read the parameters, P01 through P11, on the cover of the DCTU that you removed.
(2) Write the parameters, P01 thru P11, in the applicable location on the cover of the new DCTU.
(a) If recalibration has occurred and the data recorded on the DCTU label requires update,
replace the DCTU data label and record the correct data on the new label.
(3) At the rear of the DCTU, connect the electrical connector for the airplane wire bundle.
(4) Connect the DCTU to the rear of the fuel quantity indicator.
(5) Set the CAL-RUN jumper or the DCTU to the CAL position.
(6) Close these circuit breakers and remove the DO-NOT-CLOSE tags:
(a) P6 Main Power Distribution Panel
1) FUEL
QTY
2) EP GND FUELING
(7) Do the procedure: "Enter the Parameters into the DCTU” for the parameters P01 thru P11.
C. Enter the Correct Parameters Into the DCTU
(1) Push the UP button and the DOWN button on the DCTU at the same time.
CAUTION:
MAKE SURE BOTH BUTTONS ARE DEPRESSED AT THE SAME TIME. IF BOTH
BUTTONS ARE NOT PRESSED AT THE SAME TIME, THE VALUE OF THE
PARAMETER WILL BE CHANGED.
(2) Release the UP button and the DOWN button on the DCTU at the same time.
(a) The indicator shows the applicable parameter (for example, "P01") for one second.
(b) The indicator then shows the value for the applicable parameter.
(3) Push the UP button or the DOWN button to change the indicator display to the value that you
wrote on the cover for the applicable parameter.
(4) Do this procedure again for each of the parameters, P01 thru P11.
(5) After you enter the parameter, P11, push the two buttons at the same time.
(a) Release the two buttons at 'the same time.
(b) The indicator shows the word CAL.
Page 406
Apr 19/02
Airplanes with Smiths 2307 Model Fuel Quantity
Indicators with TSU
EFFECTIVITY
