True Refrigerator Error Code E1: LAE Probe T1 Failure
E1 on a True cabinet with an LAE control reports a problem with probe T1, the thermostat or return air probe. Check that the cabinet has power and the door is shut, read the temperature with a thermometer, and call us with the control brand, since E1 differs between controls.
Medium: without the T1 probe the compressor cycling is unreliable, so temperature can drift.
- Code
- E1
- Maker
- True
- Equipment
- Reach-in refrigerators
- Applies to
- LAE control
What does True error code E1 mean?
On an LAE control, E1 means probe T1, the thermostat or return air probe, is not reporting. The T-49-HC reach-in and the GDM-26-HC glass door merchandiser carry this control. The probe is how the control knows what the cabinet air is doing. When the signal is lost, the control cannot cycle the compressor by temperature, so the cabinet may run too long or stop too soon. The result can be a box that gets colder than set, or one that warms up between cycles. The same characters mean something different on other True controls, so the first job on a service call is to identify the control brand on the front. Only then does E1 point reliably to the T1 probe, its plug and the board input.
Affected models and control systems
True cabinets with an LAE control, such as the T-49-HC and GDM-26-HC. E1 reads differently on Carel and Danfoss 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 display
- Compressor running too long or stopping too soon
- Cabinet colder or warmer than the set point
- Alarm tone while the code is active
Possible causes
Listed in True's documentation
- A failed T1 probe or a loose plug where it meets the control
- Probe wiring rubbed or pinched at the fan shroud or door frame
- A T1 probe whose resistance has drifted away from its known value
- A failed probe input on the LAE board
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 probe lead flattened by a door hinge or latch
- Ice around the probe tip that insulates it from the air
- A plug loosened during a prior service visit
Safe checks before calling for service
- Check that the cabinet has power and the door is shut.
- Take a reading from a thermometer placed beside the food.
- If the cabinet is warm or very cold, move perishable food to another cooler.
- Look at the front for the control brand.
- Call us and tell us the control brand, since E1 differs between controls.
How a technician diagnoses error code E1
- Confirm the control is an LAE and note the exact code.
- Inspect the T1 probe, plug and lead.
- Measure the probe resistance against the expected value for the cabinet temperature.
- Check the wiring for chafing at the shroud and door frame.
- Test the T1 input at the board.
- Replace the probe, then the board only if the input fails.
- The T1 circuit ends at the LAE board, which is behind a panel beside powered wiring.
- A resistance check needs a meter and a reference temperature.
- Misreading E1 for a different control leads to the wrong part being replaced.
How error code E1 differs from similar codes
On Danfoss ETC controls E1 is sensor 1, and on Carel controls probe numbering begins at E0, so identify the control first.
Technical reference
- Document
- Commercial Refrigeration General Control Guide TEC_TM_001 Rev C, LAE p.110 Display Code Definitions
- Edition
- TEC_TM_001 | REV. C | EN, 09/3/2025, P#811072
- Models / control
- LAE control
- 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 E1 always a probe failure?
On an LAE control it points to probe T1. Other True controls use the same characters for different things.
Can I keep running the cabinet?
Briefly, with a thermometer inside, since temperature cycling may be off.
What should I tell you?
The control brand on the front and the cabinet model.
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.