True Refrigerator Error Code E1: Danfoss ETC Sensor 1 Defect
On a True cabinet with a current Danfoss ETC display, E1 means sensor 1 has a defect. Read the cabinet with a separate thermometer, avoid opening the door, and tell us the control brand so we know which E1 you have.
Medium: without sensor 1 the control cannot regulate the cabinet as designed.
- Code
- E1
- Maker
- True
- Equipment
- Reach-in refrigerators
- Applies to
- Danfoss ETC (current display)
What does True error code E1 mean?
On a current Danfoss ETC display, E1 means sensor 1 has a defect and is not reporting properly. The code is spelled the same as the LAE control's probe T1 message, but this is a different control and a different sensor. The ETC uses sensor 1 to regulate cabinet temperature, so without it the control cannot hold the box as designed. It may run in a fallback mode, or it may cool poorly, which is why it is wise to check product temperature while the code is showing. A technician starts with the sensor and its plug, then the wiring to the control, then the sensor input. Reading the control brand on the front is the quickest way to be sure you are looking at an ETC and not an LAE.
Affected models and control systems
True cabinets with a current Danfoss ETC display. The same E1 characters mean probe T1 on LAE controls.
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
- E1 on the Danfoss display
- Cabinet warmer or colder than normal
- Compressor running in an unusual pattern
- Alarm while the code is active
Possible causes
Listed in True's documentation
- Sensor 1 and its plug failing to report
- Wiring from the sensor to the control damaged
- A failed sensor input on the ETC control
- A sensor lead rubbed through near a fan or door frame
Other likely causes — what usually sits behind error code E1 on this control. A technician confirms which one it is before any part is replaced.
- A sensor connector loosened by vibration
- Ice or condensation around the sensor causing an unstable reading
- A sensor knocked from its position during restocking
Safe checks before calling for service
- Read the cabinet with a separate thermometer so you know how it is really holding.
- Close the door and avoid opening it more than needed.
- Note the control brand on the front so we know which E1 you have.
- Move perishable food to another cooler if the reading is out of range.
- Tell us the cabinet model when you call.
How a technician diagnoses error code E1
- Verify the control is a Danfoss ETC and read the code.
- Inspect sensor 1, its connector and lead.
- Measure sensor resistance against the expected value at cabinet temperature.
- Check the wiring from the sensor to the control for damage.
- Check the sensor input on the ETC control.
- Replace the sensor first, then the control only if the input is bad.
- Working at the ETC control means opening panels near live wiring.
- Measuring a sensor requires a meter and a reference temperature.
- The fallback mode can hide a dangerous temperature drift, so a technician confirms real cabinet temperature.
How error code E1 differs from similar codes
This is not the LAE probe T1 message that shares the same characters; the sensor and control are different.
Technical reference
- Document
- Commercial Refrigeration General Control Guide TEC_TM_001 Rev C, Danfoss ETC p.88 Display Code Definitions
- Edition
- TEC_TM_001 | REV. C | EN, 09/3/2025, P#811072
- Models / control
- Danfoss ETC (current display)
- Section
- Electronic Control (with Display) - Display Code Definitions: Carel p. 74, Danfoss ERC/ETC p. 87, Dixell p. 96, LAE p. 110
- 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 True reach-in refrigerator error codes
Is this the same E1 as on an LAE True?
No. The characters match, but the control, the sensor and the diagnosis differ.
Will the cabinet keep cooling?
It may, in fallback mode, or it may cool poorly, so watch the temperature.
Can I clear it?
No. It stays until sensor 1 reports properly.
Need help with True error code E1?
A technician confirms the cause on site and gives you the price in writing before any work starts.