Viking gate operator error codes

Viking’s L-3 is a commercial and residential slide operator, rated for gates up to 1,600 lb and 60 ft. Its control board reports problems three ways: an LCD display, a set of status LEDs, and a numbered “TS Ref#” table of checks. Start with the LCD, find the TS Ref# for the message, and do those checks.

How to read the display

From the manual (page 38):

1. Error messages are displayed first.
2. The Diagnose LED flashes once for each error message available.
3. Press the Diagnose button to scroll through all messages.

The display also shows status messages (GATE IS OPENING, CLOSED and so on), live readings (motor amps and volts, AC volts, charge and battery volts) and settings (speed, ODS sensitivity, timer, heater, lock mode).

Error messages

LCD message	Meaning (Viking)	TS Ref# checks
ERR AC LOW	24 V AC supply to the board is too low from the 115/230 V supply	1, 3, 20
ERR AC HIGH	24 V AC supply to the board is too high	1, 3, 20
ERR AC NO AC	No 24 V AC supply detected	1, 2, 4, 20
ERR CHRG HIGH	Possible problem with the charging voltage from the board	1, then call Viking
ERR CHRG CHECK 4A	4 amp fuse blown, or a battery or board problem	18, then call Viking
ERR BAT LOW	Battery is low	1, 2, 3, 4
ERR EPS2 WRONG	Positioning sensor not adjusted, a connection problem or the wrong harness	Call Viking
ERR EPS2 MISSING	Missing or damaged EPS2 cable harness	14, 17
ERR (OPN/CLS/NO) LIMIT	Open, close or both limits cleared and need setting	6
ERR FUSE 15 AMP	15 amp motor fuse blown	7, 11, 12
ERR EMI NO EMI	No EMI board detected	15
ERR EMI NO FUSE	4 amp main fuse blown on the power supply panel	2
ERR EMI NO AC	No AC voltage detected from the EMI board	20
ERR EMI Unknown	Communication problem between the EMI and control boards	21
ERR EMI PROTECT	Lightning strike protection for the EMI board needs replacing	Call Viking
ERR SENS UL RO	Problem with the required monitored sensors on the UL and/or Re-Open inputs	22
STOP BY OBSTRUCT	Gate stopped by an obstruction sensor event or an input to the UL terminal	11, 12, 13, 22
STOP BY OVERLOAD	Gate stopped by an overload of the gate system	11, 12

The TS Ref# checks

TS Ref#	What the manual says to check
1	High-voltage supply to the J-Box is within range: 100–120 V or 200–240 V
2	Remove and check the EMI fuse for continuity
3	Voltage selector on the modular power box matches the supply (115 or 230 V AC)
4	AC power switch is on
5	Power harness is connected to the control board
6	Set the limit positions
7	Motor fuse on the control board
8	Manual release switch is in the “Engage” position
9	Status LEDs and LCD: is the board receiving an input from an external device, or has the ODS been triggered?
10	Disconnect external devices to see whether the problem is the board, a device or its wiring
11	Gate, track and chain for debris or resistance; the ODS setting
12	The gate moves by hand with low resistance over its full travel
13	The limit positions
14	Positioning sensor cable for damage; clean the connection pins
15	EMI cable connected at both boards
16	LCD display for error messages
17	Positioning sensor cable connected to the EPS2 port
18	4 amp fuse on the control board
19	Adjust any setting on the board to clear wireless override settings
20	24 V AC out from the toroidal transformer and power harness
21	EMI cable and contacts between the EMI and control boards
22	The required entrapment protection sensors

Where the manual’s answer is “?”, it says the control board or EMI board may be damaged, and to call Viking technical support. Checks 1–3, 15 and 20–21 involve the high-voltage side and internal boards; leave those to an electrician or gate technician. For check 10, an entrapment sensor that turns out to be faulty must be repaired or replaced before the gate goes back into normal use.

Status LEDs that point to a cause

LED	State	Meaning (Viking)
Check Motor	Solid	Board sends power to the motor but the circuit is open (check motor fuse, manual release)
Battery Low	Solid / flashing	Batteries low / critically low
Power	Flashing / off	Running on batteries only / no power to the board
Stop	Flashing	Problem with the required monitored sensors on the UL and/or Re-Open inputs
Siren	Solid	Second consecutive obstruction detected
ODS	Solid / flashing	Obstruction detected / overload detected
Timer	Flashing	At the open limit, timer on, but not timing out because of a conflicting command
Close Limit or Open Limit	Flashing	That limit has been erased or not set
Diagnose	Flashing	Errors detected; check the LCD

If the gate stays open with the timer on, look at the input LEDs (Radio, UL, Re-Open, C Loop, Open, Stop, Close): a solid light means the board is receiving that input. Our gate opens but won’t close page explains how held inputs block closing.

When to call Viking

The manual lists Viking technical support at 1-800-908-0884. Call when a message’s check is “?”, when the EMI board or its protection needs replacing, or when an error returns after the listed checks.

More help

• Any brand: gate opener not working and gate stops halfway.
• Low-voltage and long runs: check wire size with the wire size calculator.
• Arm openers: Mighty Mule troubleshooting.