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Error code reference

Sirius Refrigerator Error Code AL

Ambient thermistor failure (open or short circuit detected at startup or during operation).

Sirius codesSirius refrigerator codes

Ambient thermistor failure (open or short circuit detected at startup or during operation).

First step from the service manual

Check ambient thermistor resistance against the thermistor value table; control will continue operating normally without low ambient process.

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

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What AL means on a Sirius refrigerator

The AL error code on a Sirius refrigerator indicates a failure detected in the ambient thermistor circuit. The ambient thermistor is a temperature-sensing resistor located in the area surrounding the refrigerator, typically near the condenser or in the machine compartment, and it measures the environmental temperature in which the unit operates. The control board monitors this sensor continuously, both at startup and during normal operation. When the board detects an open circuit (infinite or very high resistance) or a short circuit (near-zero resistance) in the thermistor circuit, it logs the AL code.

The ambient thermistor plays a specific role in what is called the low ambient process, a control strategy that adjusts compressor and fan cycling behavior when surrounding temperatures drop significantly, such as in garages or unheated spaces during winter. When this sensor fails, the control board loses the ability to implement those cold-ambient adjustments, but it is designed to continue operating normally in all other respects. The refrigerator will maintain its primary cooling functions even with this fault active.

Diagnosing AL begins with measuring the ambient thermistor's resistance and comparing that reading to the thermistor value table for the specific unit. A thermistor in good condition will show a predictable resistance value that changes with temperature following a known curve. A reading that is open (no continuity) or shorted (essentially zero ohms) confirms sensor failure. The wiring harness connecting the thermistor to the control board should also be inspected for corrosion, breaks, or loose terminals before condemning the sensor itself.

Source: manufacturer service documentation.

Common causes of AL

  1. 01

    Failed ambient thermistor

    Part replacement

    The thermistor itself has failed internally, producing either an open or shorted circuit. Resistance measured at the sensor terminals will not match the expected value from the thermistor table, confirming the component has failed.

  2. 02

    Damaged wiring harness or connector

    Wiring / connection

    The wiring between the ambient thermistor and the control board may have a break, short, or corroded connector. Visually inspect the harness for pinched wires, rodent damage, or terminal corrosion, and check continuity through each wire.

  3. 03

    Loose or disconnected connector

    Wiring / connection

    The thermistor plug may have worked loose from the control board or the sensor itself over time due to vibration. Reseating the connector and clearing the code is a quick first check before further testing.

  4. 04

    Moisture or corrosion at the sensor

    Wiring / connection

    In humid environments or units installed in garages, moisture can corrode the thermistor terminals and alter its resistance outside of acceptable limits. Inspect the sensor housing and terminals for oxidation or water intrusion.

  5. 05

    Control board fault

    Part replacement

    If the thermistor and all associated wiring test correctly against the thermistor value table, the control board's input circuit for the ambient sensor may have failed. This is the least common cause and should be considered only after the sensor and wiring are ruled out.

See the test procedure for each cause

Frequently asked questions about AL

What does AL mean on a Sirius refrigerator?
AL indicates that the control board has detected an open or short circuit in the ambient thermistor, the sensor that measures the room temperature around the refrigerator. This fault is detected either at startup or during normal operation. The refrigerator will continue to cool normally, but the low ambient process, which adjusts operation in cold environments, will not function until the fault is resolved.
Will my Sirius refrigerator still work with the AL error code active?
Yes, the control board is designed to continue operating normally when the AL code is present. The primary cooling functions, including compressor operation and temperature control inside the refrigerator and freezer, are not affected. The only capability lost is the low ambient adjustment process, which is relevant mainly for units operating in cold garages or similar spaces.
How do I fix the AL error on a Sirius refrigerator?
Start by checking the ambient thermistor's resistance with a multimeter and comparing it to the thermistor value table for your unit. Also inspect the wiring harness and connectors between the sensor and the control board for damage, corrosion, or loose connections. If the sensor resistance is out of specification or the circuit is open or shorted, the thermistor will need to be replaced. If the sensor and wiring both test correctly, the control board may require further evaluation.
Is the AL error code on a Sirius refrigerator a safety concern?
The AL code is not a safety hazard. The refrigerator continues to cool and operate normally with this fault present. It does indicate a component failure that should be addressed, particularly if the unit is installed in a location that experiences cold ambient temperatures, since the low ambient compensation will not be active until the sensor is repaired.
Will resetting the Sirius refrigerator clear the AL error code?
A power reset may temporarily clear the AL code from the display, but if the ambient thermistor circuit is still open or shorted, the code will return when the control board checks the sensor again at startup or during operation. A lasting repair requires either fixing the wiring connection or replacing the faulty thermistor.

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