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Error code reference

Sub-Zero Refrigerator Error Code 90 L 38

Accent lights output fault on control board.

Sub-Zero codesSub-Zero refrigerator codes

Accent lights output fault on control board.

First step from the service manual

Check if accent lights are working. Replace control board if fault is active.

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
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What 90 L 38 means on a Sub-Zero refrigerator

Error code 90 L 38 on a Sub-Zero refrigerator indicates a fault in the accent lights output circuit on the control board. The control board continuously monitors the output signals it sends to the accent lighting system. When the board detects an abnormal condition on that output, such as an open circuit, a short to ground, or a failure in the driver circuit itself, it logs this fault code and alerts the user. The accent lights are decorative interior or exterior illumination features distinct from the standard food compartment lighting.

The most direct cause of this fault is a failure within the accent lights output driver on the control board itself, meaning the board cannot deliver proper voltage or current to the accent light circuit. However, the fault can also be triggered by problems in the wiring harness connecting the board to the accent lights, or by a failed accent light assembly drawing excessive current or presenting an open circuit back to the board.

Diagnosis begins by verifying whether the accent lights are physically functioning. If the lights are completely dark or flickering when they should be on, and the fault code remains active after a power reset, the control board is the primary suspect for replacement. If the lights appear to work normally but the fault persists, inspect the wiring harness and connectors between the board and the accent light circuit for damage, corrosion, or loose terminals before condemning the board.

Source: manufacturer service documentation.

Common causes of 90 L 38

  1. 01

    Failed control board accent light output

    Part replacement

    The driver circuit on the control board responsible for powering the accent lights can fail internally, producing this fault even when wiring and light assemblies are intact. This is the most common cause when the fault remains active after a power reset.

  2. 02

    Failed accent light assembly

    Part replacement

    A burned-out or shorted accent light module can present an abnormal load back to the control board, triggering the output fault. Inspect the accent light assemblies for visible damage or failed bulbs or LEDs.

  3. 03

    Damaged or loose wiring harness

    Wiring / connection

    Wiring between the control board and the accent light circuit can develop open connections, shorts, or corroded terminals. Inspect all connectors and harness segments in the accent light circuit for physical damage or poor contact.

  4. 04

    Short circuit in accent light wiring

    Wiring / connection

    A wire pinched against a metal cabinet edge or refrigerator liner can create a short to ground, causing the board to detect a fault on that output. Trace the wiring path carefully for any points of contact with sharp or conductive surfaces.

See the test procedure for each cause

Frequently asked questions about 90 L 38

What does 90 L 38 mean on a Sub-Zero refrigerator?
Error code 90 L 38 indicates a fault in the accent lights output circuit on the refrigerator's control board. The board has detected an abnormal electrical condition on the circuit that powers the accent lighting, such as an open circuit, a short, or an internal driver failure. The accent lights may be non-functional when this code is active. The first step is to check whether the accent lights are working and to replace the control board if the fault remains active.
Can I fix error code 90 L 38 myself, or do I need a technician?
A knowledgeable DIYer can start by inspecting the wiring harness and connectors between the control board and the accent light assemblies for loose terminals or visible damage. If the wiring is intact and the fault persists, the repair typically requires replacing the control board, which involves working with the refrigerator's electrical components. If you are not comfortable with appliance electrical diagnosis, having a qualified technician perform the repair is the safer choice.
Will resetting my Sub-Zero refrigerator clear error code 90 L 38?
A power reset may temporarily clear the fault code, but if the underlying problem with the accent light output circuit still exists, the code will return. A persistent fault after reset points to a hardware failure in the control board or the accent light circuit components. Resetting is useful for confirming whether the fault is intermittent, but it does not resolve the root cause.
Is error code 90 L 38 a safety concern for my refrigerator?
This fault is specific to the accent lighting output and does not directly affect the refrigeration system, compressor, or temperature control functions. Your food should remain safely stored while this fault is present. However, if the fault is caused by a short circuit in the wiring, it is worth addressing promptly to prevent any potential for further electrical issues within the unit.
How much does it cost to repair error code 90 L 38 on a Sub-Zero refrigerator?
If the repair requires a new control board, parts and labor costs for a Sub-Zero refrigerator typically range from several hundred dollars to over a thousand dollars depending on the specific model and your location. If the fault is caused by a wiring issue or a failed accent light assembly, the cost may be lower. Getting a diagnosis from a certified Sub-Zero service technician will help pinpoint the exact component needed before committing to parts costs.

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