12
Code
Meaning
Symptom
Solution
Saved
LIFTMASTER SYSTEM
41
Battery overcurrent
Code 41 will show up on the
diagnostic display. There will
possibly be low battery voltage
(the LOW BATT LED will be on).
Possible short of the battery charge harness. Check harness.
Make sure the recommended battery(ies) are being used. Make
sure you do NOT have a 12V battery on a 24V system. Check
battery fuse.
TEST: After checking the batteries, check for code 41 on the
diagnostic display.
YES
42
No battery at boot up
Operator will run and the
diagnostic display will show
Code 42 with power cycle or
boot-up. The operator will not
run on battery backup after
power loss.
Check the battery connections at the main control board and at
the battery terminals. Make sure the J15 plug is plugged into
the board. Replace batteries if depleted to less than 20V on a
24V system or less than 10V on a 12V system. Make sure there
is NOT a single 12V battery on a 24V system.
TEST: After checking the batteries, check for code 42 on the
diagnostic display.
YES
INSTALLED SYSTEM
43
Exit Loop Error
Gate will lock in the open
position or closed position
(depending on the dip switch
setting). The exit loop will not
be functional and diagnostic
display will show Code 43.
LiftMaster Plug-in Loop Detector only. Failure or missing loop.
Check loop wiring throughout connection. May be a short in the
loop, or an open connection in the loop.
YES
44
Shadow Loop Error
All Operators:
Gate will not
close.
Models LA400U, LA412U,
LA500U, RSW12U:
Gate will
not open.
45
Interrupt Loop Error
Gate will not close.
46
Wireless edge battery
low
The operator will beep 2 times
with a command. Critically low
battery will cause gate to latch
open or closed depending on
the board settings (Batt Fail
switch settings on DC operator
control board and Exit Fail
switch setting on the AC
operator expansion board).
Replace batteries in wireless edge.
YES
LIFTMASTER SYSTEM
47
Fault detected in the
power board.
Operator will not run.
Replace the power board.
YES
50
Run-Distance Error
Gate will stop prior to reaching
the desired limit setting.
DC Operators:
Gate unbalance detected. Make sure the gate is
installed on a level surface and not on an excessive grade.
YES
AC Operators:
The limits are less than the minimum
requirement or longer than what was learned. Check limit
positions and proper switch function. Run-distance can be
re-learned by setting the handing again.
INFORMATIONAL
51
Pass-point not detected
(Operator 1)
Operator runs at a constant
slow speed.
Check yellow pass-point wiring. If limits are not accurate,
reprogram.
NO
52
Pass-point not detected
(Operator 2)
53
Brownout occurred
Operator will run and show
code 53.
AC/DC board supply dipped below allowable level. Review
power supply and wiring. If rebooting, ensure enough time for
discharge of power to force a fresh boot.
YES
54
Wireless Second
Operator Communication
Error
Only the commanded operator
will respond.
Check the second operator for power. If OFF, restore power and
try to run the system. If powered, deactivate the wireless
feature and then reprogram the second operator.
YES
Some codes are saved in the code history and some are not. If a code is not saved it will briefly appear on the display as it occurs, then disappear.
When servicing of the operator is complete, erase the code history by pressing the STOP button until the display flashes “Er” then “CL” (about 6
seconds). When the codes have been erased the display will show “_ _”.
DIAGNOSTIC CODES
