Sub-Zero error code · 45 1 00
Sub-Zero Code 45 1 00: Refrigerator Main Lights Open Circuit
Sub-Zero code 45 1 00 means the refrigerator main lights circuit reads open. Usual cause: a failed LED light module or broken wiring; check lights and wiring.
Sub-Zero code 45 1 00 means the refrigerator main lights circuit is reading open, so the board sees no continuity to the lights. The usual fix is to repair the light wiring or replace the failed refrigerator LED light module after checking the lights and harness.
45 1 00, explained
The board monitors the refrigerator main lighting circuit for continuity. An open-circuit reading means the LED light module or its wiring has lost continuity, so the lights do not illuminate. The board logs 45 1 00 to flag the open lighting load. It points to the light module or wiring rather than a sealed-system or cooling fault.
Severity:Minor
How 45 1 00 shows up
- Refrigerator interior lights stay off when the door opens
- One or more main light modules dark while others work
- Flickering then total loss of refrigerator lighting
- Diagnostic code 45 1 00 stored in the service menu
- No SERVICE light, since cooling is unaffected
What usually causes it
- Failed refrigerator LED light module
- Broken or disconnected light wire
- Loose or corroded light connector
- Wiring fatigue at a door or hinge flex point
- Moisture corrosion at the light circuit
Which part 45 1 00 points to
- Refrigerator LED light module — Replaced when a light module measures open or fails to illuminate
- Light circuit wiring / connector — Repaired or replaced if a broken wire or loose connector caused the open circuit
Why 45 1 00 appears
LED light modules fail open when the internal LEDs or driver age out, and the circuit can also open at a loose or corroded connector or a broken wire. Repeated door cycling can fatigue wiring at flex points, and moisture intrusion can corrode the light connections.
What you can safely check
- Confirm the lights are truly off and not dimmed by a setting
- Note the code and which compartment lights are affected
- Power-cycle the unit at the breaker and check whether the lights return
- Confirm the door switch is not stuck reporting the door as closed
When 45 1 00 needs a technician
Confirming an open lighting circuit and replacing an LED module requires testing the harness and accessing the light assembly, which is technician work though cooling is not affected.
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Frequently asked
Sub-Zero 45 1 00 — questions
What does Sub-Zero code 45 1 00 mean?
Code 45 1 00 means the refrigerator main lights circuit is reading open, so the control board sees no continuity to the lights. The board monitors the main lighting load, and an open reading means the LED light module or its wiring has lost continuity, so the lights don't illuminate. It points to the light module or harness, not a sealed-system or cooling fault, which is why there's no SERVICE light.
Can I fix a 45 1 00 myself?
The repair is a technician task, but start with simple checks. Confirm the lights are truly off and not just dimmed by a setting, note which compartment is affected, power-cycle at the breaker to see if they return, and check that the door switch isn't stuck reporting the door as closed. Confirming an open lighting circuit and replacing an LED module needs harness testing and access to the light assembly.
How do I clear code 45 1 00?
A breaker power-cycle may clear 45 1 00 momentarily, but if the LED module or its wiring is genuinely open the code returns when the board rechecks the lighting circuit. It clears for good only after the failed module or broken wire is repaired or replaced and the code is reset in the service menu.
Is 45 1 00 safe to leave alone?
Yes. It is low severity because only the interior lighting is affected; cooling runs normally, there's no SERVICE light, and food stays safe. The single consequence is the refrigerator interior lights staying dark when the door opens. It is fine to keep using the unit, and you can schedule the lighting repair at your convenience.
Which part does 45 1 00 involve and what does it cost?
The parts are the refrigerator LED light module when it measures open or won't illuminate, or the light circuit wiring and connector if a wire broke at a door flex point or a plug loosened. We test the harness and module for a flat $89 diagnostic, back the repair with a 365-day warranty, and answer at (650) 668-1554.
How is 45 1 00 different from the lights short code 45 1 01?
Both involve the refrigerator main lights but in opposite ways. 45 1 00 is an open circuit, meaning continuity is lost and the lights simply stay dark, usually from a failed LED module or broken wire. 45 1 01 is a short, where the load draws too much current from pinched wiring. A technician confirms 45 1 00 by reading the lighting circuit as open rather than shorted.
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