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Error code reference

Sub-Zero Refrigerator Error Code 15 1 01

Refrigerator Compressor Relay is stuck closed; power to compressor at all times.

Sub-Zero codesSub-Zero refrigerator codes

Refrigerator Compressor Relay is stuck closed; power to compressor at all times.

First step from the service manual

Verify, replace control board.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
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What 15 1 01 means on a Sub-Zero refrigerator

Error code 15 1 01 on a Sub-Zero refrigerator indicates that the refrigerator compressor relay has been detected in a stuck-closed condition. Under normal operation, the control board cycles the compressor relay open and closed to regulate compressor run time based on cooling demand. When this relay becomes stuck in the closed position, it creates a continuous electrical path to the compressor, meaning the compressor receives power at all times regardless of the control board's commands.

A compressor running without interruption cannot complete normal defrost cycles, causes excessive wear on compressor components, and may result in the refrigerator running too cold or freezing food in the fresh food compartment. The relay itself is typically integrated into or controlled through the main control board's output circuitry. When the board loses the ability to open the relay circuit, it flags this fault to alert technicians that compressor operation is no longer under proper supervisory control.

The primary diagnostic path for this code points directly to the control board. A failed relay driver transistor, a shorted relay coil circuit, or a welded relay contact within the board assembly can all produce this fault. Because the relay is part of the control board's integrated circuitry rather than a standalone serviceable component, the standard corrective action is verification of the fault condition followed by control board replacement. Technicians should confirm the fault is active and not a transient condition before proceeding with the board swap.

Source: manufacturer service documentation.

Common causes of 15 1 01

  1. 01

    Failed control board relay circuit

    Part replacement

    The relay driver circuit or the relay contact on the control board has failed in a closed state, preventing the board from cutting power to the compressor. This is the most common cause and is confirmed by the board being unable to cycle the compressor off.

  2. 02

    Welded relay contacts on the control board

    Part replacement

    High current draw events or compressor startup surges can cause the relay contacts inside the board to weld together, permanently closing the circuit. The compressor will run continuously and cannot be shut off by normal board commands.

  3. 03

    Shorted relay coil or driver transistor

    Part replacement

    A short in the relay coil winding or the transistor that drives it can hold the relay in the energized position. This is an internal board-level failure that cannot be repaired without board replacement.

  4. 04

    Transient control board fault

    Wiring / connection

    In rare cases, a temporary power surge or software glitch can trigger a false 15 1 01 reading. Verifying whether the fault condition is truly active before replacing the board helps rule this out.

See the test procedure for each cause

Frequently asked questions about 15 1 01

What does 15 1 01 mean on a Sub-Zero refrigerator?
Error code 15 1 01 means the refrigerator compressor relay is stuck in the closed position, causing the compressor to receive power continuously. The control board is unable to cycle the compressor off as it normally would during temperature regulation. This is a control board-level fault that requires diagnosis and typically board replacement to resolve.
Can I fix error code 15 1 01 myself?
The primary fix for this code is replacing the control board, which requires disconnecting electrical components and working with line-voltage wiring. Technicians with appliance repair experience can perform this repair, but most homeowners should call a qualified service technician. Confirming the fault is active before ordering parts is an important first step.
Is it safe to keep using my Sub-Zero refrigerator with error code 15 1 01 active?
Continued operation with this fault is not recommended. A compressor running without shutting off generates excessive heat, accelerates wear, and can lead to compressor failure or food being over-chilled. It also increases energy consumption significantly. The refrigerator should be serviced promptly to prevent further damage.
Will resetting my Sub-Zero refrigerator clear error code 15 1 01?
A power cycle reset may temporarily clear the code, but if the relay circuit on the control board has physically failed, the fault will return quickly because the underlying hardware problem remains. If the code reappears after a reset, the control board should be inspected and replaced. Resetting the unit does not repair a stuck relay contact.
How much does it cost to fix error code 15 1 01 on a Sub-Zero refrigerator?
Repair costs depend on the specific Sub-Zero model and local labor rates. Control board replacement on Sub-Zero refrigerators typically ranges from several hundred dollars to over a thousand dollars when factoring in the cost of the board and professional labor. Getting a quote from an authorized service provider before proceeding is advisable.

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