35
Diagnostic Codes Table
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.
LiftMaster System
Installed System
Informational
External Entrapment
Protection
Inherent Entrapment
Protection
Code
Meaning
Solution
Saved
31
Main control board has experienced an internal
failure.
Disconnect all power, wait 15 seconds, then reconnect power (reboot). If
issue continues, replace main control board.
NO
32
Linear Drive Disengaged (Arm 1)
Disengage then re-engage arm. Check wiring and connections.
YES
33
Linear Drive Disengaged (Arm 2)
35
Max-Run-Time Exceeded Error
Check for an obstruction, then reprogram the limits.
YES
36
Product ID Error
Was the control board just replaced? If so, erase limits, enter limit setup
mode and set limits. If not, disconnect all power, wait 15 seconds, then
reconnect power before changing product ID harness.
YES
37
Product ID Failure
Unplug product ID harness then plug back in. Disconnect all power, wait
15 seconds, then reconnect power before replacing product ID harness.
YES
38
Hard Stop Limit (Arm 1)
Limit may be set too tightly against a non-resilient hard stop (re-adjust
limit). Operator may be at end of travel (re-adjust mounting).
NO
39
Hard Stop Limit (Arm 2)
40
Battery overvoltage
Too much voltage on the battery. Check harness. Make sure there is NOT a
24V battery on a 12V system.
YES
41
Battery overcurrent
Possible short of the battery charge harness. Check harness. Make sure
you do NOT have a 12V battery on a 24V system.
YES
42
No battery at boot up
Check battery connections and installation. 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.
YES
43
Exit Loop Error
Failure or missing loop (SHORT or OPEN - LiftMaster Plug-in Loop
Detector only) Check loop wiring throughout connection. May be a short
in the loop, or an open connection in the loop.
YES
44
Shadow Loop Error
45
Interrupt Loop Error
46
Wireless edge battery low
Replace batteries in wireless edge.
YES
51
Pass-point not detected (Arm 1)
Check yellow pass-point wiring. If limits are not accurate, reprogram.
NO
52
Pass-point not detected (Arm 2)
53
Brownout occurred
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
Check the second operator for power. If OFF, restore power and try to run
the system. If powered, deactivate the wireless feature and then re-learn
the second operator.
YES
60
Minimum number of monitored entrapment
protection devices not installed.
Review monitored entrapment protection device connections. This swing
gate operator will operate only after installation of a minimum of one
external safety device in either the open or close direction.
NO
61
CLOSE EYE/INTERRUPT held more than 3 minutes
Check wired input on main control board; check for alignment or
obstruction.
YES
62
CLOSE EDGE held more than 3 minutes
63
OPEN EYE/EDGE held more than 3 minutes
64
CLOSE EYE/INTERRUPT held more than 3 minutes
Check wired input on expansion board; check for alignment or
obstruction.
YES
65
CLOSE EYE/EDGE held more than 3 minutes
66
OPEN EYE/EDGE held more than 3 minutes
67
Wireless edge triggered more than 3 minutes
Check wired input for wiring issue or obstruction.
YES
68
Wireless edge loss of monitoring
Check wireless edge inputs.
YES
TROUBLESHOOTING
