Error code reference

Sub-Zero Refrigerator Error Code 40 3 40

Zone 3 excessive compressor runtime.

SourceSub-Zero Original (7031215): Prior to Serial 5623000: Service Manualp. 7-8

Sub-Zero codes Sub-Zero refrigerator codes

Diagnostic procedure

The full 40 3 40 procedure

Step 1 is visible so you can confirm you are on the right page. The remaining steps, the ones that tell you whether to actually replace a part, unlock with any pass.

MyPros+ · DiagnosticsStep 1 preview

First diagnostic step

Verify performance of unit and check: door leaks, door ajar, evaporator fan, condenser fan, frozen evaporator, cabinet and evaporator thermistors, system charge.

SourceSub-Zero Service Manual: PRO4850 (Vol. 7): Service Manual

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More steps, wiring diagram references, and verified part numbers

Includes expected resistance and voltage values, connector pinouts, and supersession notes for replacement parts.

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Where this code is documented

11 manuals in the MyPros+ library document this code for Sub-Zero refrigerator.

Models covered by the manuals that document this code

More models are covered than are listed here.

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The full 40 3 40 procedure

Where this code is documented

Models covered by the manuals that document this code

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