Diagnostic or test mode is a service-level mode that allows technicians to command individual components — fans, heaters, valves, the compressor — to run independently for testing purposes. If a refrigerator is left in test mode, it will not operate normally.
What Triggers This Code?
Test mode is entered through a specific button sequence documented in the service manual (not the user manual). It can be entered accidentally by pressing the right combination of buttons during cleaning or troubleshooting.
Signs That Test Mode Is Active
- The display shows cycling numbers, dashes, or unusual alphanumeric codes
- Components switch on and off in a programmed sequence regardless of actual temperatures
- The refrigerator may cool erratically or not at all during the test cycle
- Fans, compressors, or heaters activate unexpectedly
Solutions
- Do not leave the refrigerator in test mode: It is not designed for normal operation in this state and will not protect food properly.
- Exit test mode: In most cases, unplugging the refrigerator and plugging it back in resets it to normal operation.
- Alternatively, complete the test cycle: Some brands cycle through test mode automatically and return to normal operation after a set period (typically 2–5 minutes).
- Consult the service sheet: If a power cycle does not resolve it, the service sheet (often taped inside the refrigerator or downloadable by model number) documents the test mode exit sequence.