37
TROUBLESHOOTING
DIAGNOSTIC CODES continued...
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.
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)
34
Absolute Position Encoder Error, not
getting position information from encoder
Check APE assembly and wiring connections. Replace the APE assembly if
necessary.
YES
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
50
Run-Distance Error
Gate unbalance detected. Make sure the gate is installed on a level surface and
not on an excessive grade.
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 reprogram the
second operator.
YES
LiftMaster System
Installed System
Informational
External Entrapment
Protection
Inherent Entrapment
Protection