True Refrigerator Error Code E3: LAE Probe T3 Failure
E3 on a True LAE control means probe T3, the display or multifunction probe, is not reporting. The cabinet usually keeps cooling from the main probe. Confirm it holds temperature with a thermometer and call us with the model number.
Medium: the cabinet usually keeps cooling, but the extra reading and display accuracy are lost.
- Code
- E3
- Maker
- True
- Equipment
- Reach-in refrigerators
- Applies to
- LAE control
What does True error code E3 mean?
On an LAE control, E3 means probe T3, the display or multifunction probe, is not reporting. It shows on models like the T-49-HC reach-in and the GDM-49-HC glass door merchandiser. The T3 probe is the third sensor on the control and gives an extra reading, so the cabinet usually keeps cooling from the main probe. What you see is the code, and sometimes an alarm, plus a display that may not match the real conditions inside. Because the main cooling decision does not depend on T3, the urgency is lower than for T1, but the extra reading is gone until the probe is repaired. A technician checks the T3 probe and connector, the wiring to the board, and the board input, and asks whether the probe was moved earlier.
Affected models and control systems
True cabinets with an LAE control, such as the T-49-HC and GDM-49-HC. T3 is the third probe.
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
- E3 on the display
- Display reading that seems off
- Alarm tone
- Cabinet otherwise cooling normally
Possible causes
Listed in True's documentation
- The T3 probe and its connector
- Wiring between the probe and the board
- The T3 input on the control
- A probe that was moved or reconnected during earlier service
Other likely causes — what usually sits behind error code E3 on this control. A technician confirms which one it is before any part is replaced.
- A T3 probe lead unplugged when a panel was removed for cleaning
- Condensation in the T3 connector
- A probe left unclipped after an earlier repair
Safe checks before calling for service
- Confirm the cabinet is holding temperature with a thermometer.
- Check that the door closes fully.
- Press a button if the alarm is sounding.
- If E3 stays on, call us to schedule service.
- Give us the model number from the data plate.
How a technician diagnoses error code E3
- Read the code and confirm the control is an LAE.
- Check the cabinet temperature on an independent thermometer.
- Inspect the T3 probe, connector and lead.
- Measure the probe resistance against the expected value.
- Check the wiring and the T3 input at the board.
- Replace the probe, and the board only if the input fails.
- The T3 circuit ends at the control board behind a panel with powered wiring.
- Measuring the probe needs a meter and a reference.
- Knowing which probe belongs to which input comes from the control's own wiring data.
How error code E3 differs from similar codes
E3 means a different probe or sensor on other controls, so it is read together with the control brand.
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 E3 serious?
Usually less than E1, since the main probe controls cooling, but the extra reading is lost.
Can I silence it?
You can press a button for the alarm, but the code stays until the probe reports.
Why does the display look wrong?
T3 provides an extra reading, so the display may not match real conditions.
Need help with True error code E3?
A technician confirms the cause on site and gives you the price in writing before any work starts.