Manual
ACR ELECTRONICS, INC / ARTEX PRODUCTS
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
C406-1 (453-5002), C406-1HM (453-5003)
25-62-10
Page 48 of 90
JUL 31/12
TASK 25-62-10-810-801
3. Fault Isolation
SUBTASK 25-62-10-810-001
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.
Table 6. ELT Self-Test Error Codes Troubleshooting Guide
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










