Kolpak Walk-In Cooler Error Code DISPLAY AUX2 SENSOR: Display AUX2 Shorted or Open
DISPLAY AUX2 SENSOR means the Display AUX2 Function is set to a temperature input and the input is shorted or open. The controller cannot read the sensor on that input. Press ENTER to silence the alarm for one hour and have the sensor and its wire checked.
Low: only the monitoring on one input is affected, and the room keeps cooling from its main controls.
- Code
- DISPLAY AUX2 SENSOR
- Maker
- Kolpak
- Equipment
- Walk-in coolers & freezers
- Applies to
- ArcticFox OEM Controller with Deluxe Display (Kolpak walk-ins)
What does Kolpak DISPLAY AUX2 SENSOR mean?
The Deluxe Display has its own auxiliary inputs, separate from the Main board. When Display AUX2 Function is set to a temperature input, the controller expects a temperature sensor on that input and reads its resistance to work out a temperature. If the input reads as shorted, with almost no resistance, or open, with no connection at all, the reading is outside what any real sensor would give. The controller cannot trust it and posts the text alarm DISPLAY AUX2 SENSOR in the Alarms menu. The check runs continuously. The alarm is about the sensor circuit and says nothing about the actual temperature of the room or product. Any monitoring or alarm that depends on that sensor, such as a high or low monitor alarm, cannot work while the input is shorted or open. The alarm sounds again after the one-hour silence unless the circuit is repaired.
Affected models and control systems
ArcticFox OEM Controller with Deluxe Display on Kolpak walk-ins. This alarm refers to the Display AUX2 input, not the Main AUX2 input, and is listed in the Alarms menu on page 16.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- DISPLAY AUX2 SENSOR text in the Alarms menu
- Audible alarm from the display
- Temperature reading for the Display AUX2 input missing or odd
- Related monitor alarms not working as expected
Possible causes
Likely causes — what usually sits behind DISPLAY AUX2 SENSOR on this control. A technician confirms which one it is before any part is replaced.
- Temperature sensor on Display AUX2 unplugged or its wire broken
- Sensor wire pinched or shorted against metal
- Corroded sensor connector in a damp walk-in
- Display AUX2 Function set to a temperature input although no sensor was installed
Safe checks before calling for service
- Press ENTER to silence the alarm for 1 hour. It sounds again if the sensor circuit is not corrected.
- If the sensor wire is visible, look for a cable that has been pulled loose or crushed. Do not unplug or cut anything.
- Note whether the alarm began after cleaning, moving shelves, or a door impact.
- Give the technician the exact text DISPLAY AUX2 SENSOR and tell them whether you know what the sensor monitors.
How a technician diagnoses DISPLAY AUX2 SENSOR
- Read the Display AUX2 Function setting and confirm it is a temperature input.
- Locate the sensor and its wiring and inspect for damage and moisture.
- Disconnect the sensor and measure its resistance, comparing it with the sensor chart for the temperature at hand.
- Check the wire for continuity and shorts to ground.
- Replace the sensor or repair the wiring, or change the function if no sensor belongs there.
- Sensor wiring lands inside the Display and controller, which should not be opened by anyone except a technician.
- Telling a shorted sensor from an open wire takes a meter reading against a resistance chart.
- Changing the input function in the controller menus affects alarms and should match the installation.
Technical reference
- Document
- ArcticFox Deluxe Display - Original Instructions, Installation, Operation and Maintenance Manual
- Edition
- Part No. 500002385-4, 5/23
- Models / control
- ArcticFox OEM Controller with Deluxe Display (Kolpak walk-ins)
- Section
- ArcticFox OEM Controller - Alarms Menu, p.16
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Kolpak walk-in cooler & freezer error codes
Is the temperature in my walk-in wrong?
Not necessarily. The alarm says the Display AUX2 sensor circuit is shorted or open. The room may be fine.
Is this the same as AUX2 SENSOR?
No. DISPLAY AUX2 SENSOR is about the Display input. AUX2 SENSOR is the matching alarm for the Main board input.
Can I unplug the sensor to stop the alarm?
No. An unplugged sensor is an open circuit and will keep the alarm active.
Need help with Kolpak DISPLAY AUX2 SENSOR?
A technician confirms the cause on site and gives you the price in writing before any work starts.