Aircraft Power; Mode Selections, Cdu System Id Program Pins - Garmin G3X Touch Installation Manual

25.3.2

Aircraft Power

The GDU 37X can operate using power from one or both inputs (AIRCRAFT POWER 1 AND
AIRCRAFT POWER 2). The pins are internally connected using diodes to prevent current from flowing
between the two power inputs. AIRCRAFT POWER 2 is for connecting to an alternate power source, such
as on aircraft with two electrical buses.
AIRCRAFT POWER 1
AIRCRAFT POWER 2
POWER GROUND
POWER GROUND
25.3.3

Mode Selections, CDU System ID Program Pins

In a single-display system, configure the display as PFD1. In a two display-system, configure one display
as PFD1 and the other display as MFD. In a three-display system, one display is PFD1, one is the MFD,
and the third is PFD2.
Configure the GDU 37X units per the following tables.
A GDU 37X can be manually placed in reversionary mode by wiring Pin 25 to a two pole switch that
toggles between open and ground. When the switch is open, the display will operate normally. When the
switch is grounded, the display changes to reversionary mode, showing the engine bar at the top of the
display and a split screen PFD and MFD below. Other displays in the system will not be affected by
manually placing a display into reversionary mode.
Do not connect a switch to ground for pins 9 or 10, doing so can cause communication errors.
Grounding pin 42 will place the GDU 37X in Demo mode, which is for in-store demonstration use only,
never ground pin 42 in an aircraft installation.
CDU SYSTEM ID
PROGRAM* 1, J3701 Pin 10
Open
Ground
Open
Ground
CDU SYSTEM ID
PROGRAM* 3
J3701 Pin 25
Open
Ground Forced Reversionary
190-01115-01
Rev. AC
Pin Name
CDU SYSTEM ID
PROGRAM* 2, J3701 Pin 9
GDU Mode
Auto Reversionary
Connector
J3701
J3701
J3701
J3701
Open
Open
Ground
Ground
CDU SYSTEM ID
PROGRAM* 4
J3701 Pin 42
Open
Ground
G3X/G3X Touch Installation Manual - LRU Pinouts
Pin I/O
32 In
31 In
15 --
16 --
GDU Mode
MFD
PFD1
PFD2
Do Not Use
GDU Mode
Normal Operation
Demo Mode
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