ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
C406-2 (453-5000), C406-2HM (453-5001)
570-5000 Rev. U
Company Confidential
25-62-11
Page 34 of 66
TASK 25-62-11-810-801
3.
Fault Isolation
SUBTASK 25-62-11-810-001
A.
Self-Test Error Troubleshooting Guidelines
1)
Table 6 describes the ELT self-test LED error codes (i.e., flash codes), their probable causes, and
possible solutions. The 5-flash error is not present when the ELT is programmed with a serial user
protocol (short message).
NOTE:
Upon activation, the LED will display a long single flash, which is normal. Any self-
test error codes will display following this initial flash. Do not confuse the initial flash
with a 1-flash error code. If there are multiple errors, there is a 0.5 to 1.0 second
pause between each error code.
CODE
PROBABLE CAUSE
POSSIBLE SOLUTION
1-Flash
Indicates a G-switch loop open (Pins 5 and 8)
Remote switch harness connector
loose or disconnected at ELT
Check connector and tighten as necessary
ELT connector pins bent or broken
Check condition of connector pins and repair or replace as
necessary
Connector pins 5 and 8 jumper open
(internal to remote switch harness
connector at ELT end)
Repair open jumper
3-Flash
Indicates a 406 MHz transmission problem
Open or short condition on antenna
output or coax cable
Verify the coax cable/antenna is connected and in good
condition Perform continuity check of center conductor
and shield. Check for a shorted cable
Check for intermittent connection in the coax cable
Antenna or installation faulty
Check with a VSWR meter. Check antenna for opens,
shorts, or a resistive ground plane connection
Impedance presented by antenna
Lengthen or shorten antenna coax cable length by 4 to 6
inches
Insufficient ground plane
Provide ground plane at least 12 inches in diameter
Upright metal structure obstructing
antenna causing re-radiation
Stay at least 10-12 inches away from upright metal
structures
Low power output
Battery low
3A fuse on battery pack circuit board faulty
Improper programming
Verify 406 MHz programming
Transmitter module faulty
Cannot be repaired in field - Return to factory for
servicing
5-Flash
Indicates there is no navigation position data present
Aircraft navigation system off
Turn on navigation system
Faulty system interface wiring or
connections
Check wiring and connections for continuity and security
No 453-6500 ELT/NAV Interface
installed
Install 453-6500 ELT/NAV Interface
Reprogram to short message
7-Flash
Indicates a battery problem
Operating time is >1 hour
Replace battery pack
Electrical circuits faulty