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Error code reference

Jenn-Air Range Error Code 4d31

Cooling fan is running when it should be de-energized (cooling fan on when idle).

Jenn-Air codesJenn-Air range codes

Cooling fan is running when it should be de-energized (cooling fan on when idle).

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What 4d31 means on a Jenn-Air range

Error code 4d31 on a Jenn-Air range indicates that the cooling fan is detected as running during a period when the control system has not commanded it to operate. The cooling fan is responsible for circulating air over the control board, electronics, and other heat-sensitive components during and after high-temperature cooking cycles. The control system monitors fan operation through feedback signals, and when it detects fan motor activity outside of a commanded state, it flags this fault to alert the technician to an abnormal condition.

The most likely source of this fault is a failed relay on the control board. Relays are electromechanical switches that open and close circuits to energize components like the cooling fan. If a relay contacts weld together or stick in the closed position, the fan receives continuous power regardless of what the control board commands. This type of relay failure is a known failure mode in solid-state and hybrid control boards exposed to repeated heat cycling.

Another possible cause is a wiring fault, such as a short to voltage in the fan circuit that keeps the fan motor energized. The fan motor itself could also be contributing if it has developed an internal fault, though this is less common than a relay or wiring issue. Addressing this code promptly matters because a fan running continuously can mask other cooling system problems and may indicate the control board has broader reliability issues that could affect other components.

Source: manufacturer service documentation.

Common causes of 4d31

  1. 01

    Stuck or welded relay on control board

    Part replacement

    A relay on the main control board can fail with its contacts fused in the closed position, continuously supplying power to the fan motor. Inspect the board for visible burn marks or overheated relay components near the fan circuit.

  2. 02

    Faulty main control board

    Part replacement

    Beyond a single relay failure, the control board itself may have broader circuit damage causing it to incorrectly energize the fan output. If relay inspection does not reveal an obvious fault, board replacement is typically the next step.

  3. 03

    Short to voltage in fan wiring harness

    Wiring / connection

    A pinched, chafed, or damaged wire in the cooling fan circuit can create a short that keeps the fan motor powered independently of relay switching. Trace the wiring from the control board to the fan motor and check for insulation damage or contact with the chassis.

  4. 04

    Failed cooling fan motor

    Part replacement

    An internal fault in the fan motor, such as a shorted winding, can in some cases cause feedback signals that the control interprets as the fan running unexpectedly. Disconnect the fan motor and check for continuity and resistance values within specification.

See the test procedure for each cause

Frequently asked questions about 4d31

What does 4d31 mean on a Jenn-Air range?
Code 4d31 means the range control system has detected that the cooling fan is operating when it has not been commanded to run. This typically points to a stuck relay on the control board, a wiring fault, or a failed board that is keeping the fan circuit energized. The fan should only run during and briefly after cooking cycles, so continuous operation in an idle state is considered an abnormal condition.
Can I fix error code 4d31 myself on a Jenn-Air range?
A knowledgeable DIYer can inspect the wiring harness for visible damage and check whether the fault clears after a power reset. However, if the cause is a stuck relay or a failed control board, those repairs involve working with the main electrical board and require component-level diagnosis or board replacement. If you are not comfortable working with appliance control boards, a qualified technician is recommended.
Is error code 4d31 on a Jenn-Air range a safety concern?
A continuously running cooling fan is not an immediate fire or shock hazard, but it does indicate an abnormal electrical condition in the control system. A stuck relay or shorted circuit that causes this code could potentially affect other components over time. It is best to diagnose and resolve the fault rather than continue operating the range indefinitely with the code present.
Will resetting the range clear error code 4d31?
A power reset by disconnecting the range from the outlet for several minutes may temporarily clear the code, but if the underlying cause is a hardware fault like a welded relay or damaged wiring, the code will return. A reset is a useful first step to confirm whether the fault is intermittent or persistent, but it does not fix the root cause.
How much does it cost to repair error code 4d31 on a Jenn-Air range?
Repair costs vary depending on the root cause. If the issue is a wiring fault requiring no new parts, labor costs from a technician might range from around $100 to $200. If the main control board needs replacement, parts alone can range from $150 to $400 or more depending on the specific model, with additional labor on top of that. Getting a diagnostic visit quote before authorizing repairs is advisable.

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