Since the fans run constantly even on a Live USB ("Try Ubuntu"), the issue is almost certainly a hardware or BIOS/UEFI-level firmware behavior rather than a software problem within Ubuntu. High-performance models sometimes default to an aggressive fan curve or an "Always On" setting to remain cool.

don't forget to click the Accept Solution button

Hi

I believe the fan control is not fully achievable on that model (Dell Pro Max 14 MC14250),

however the interweb LLM suggests this...........

Short answer: You can usually stop the Pro Max 14’s fans from running full‑speed on Ubuntu 24.04 by

(1) installing Dell-specific utilities (i8kutils or dell-bios-fan-control),

(2) enabling the kernel module that exposes Dell SMM fan controls, and

(3) running a userspace fan manager (i8kmon or a systemd service) to apply temperature-based curves — but exact steps depend on whether the BIOS allows user control on your MC14250 and on whether the fans are exposed via /sys.

I am also having fan issue on my Dell Pro 14 PC14250 (dual boot win11/ubuntu 26.04). The fan running constantly is very disturbing as for me!

I really hope this will be fixed very soon. 

Have you found any solutions on how to fix this please ? 

By the way, I found this post on reddit [see attached file]

@anne_droid​ I tried it, but didn't work 😢

Windows users should run Dell Optimizer--> Thermal Management--> Quiet.

Windows and Ubuntu users should also run the F12 Diagnostics to check for fans running constantly during the diags.

@DELL-ChrisM2​ I tried run extended diagnostics, without any issue. Using Ubuntu. 

Hi peeps!

I have the same issue reported here happening in a Dell Pro Max 16 (MC16250) , BIOS 1.19.2, Ubuntu 26.04 LTS (kernel 7.0.0-34-generic).

Symptom: both chassis fans run continuously at a non-trivial, fixed speed (~1960–2130 RPM out of a 4200 RPM max) regardless of actual load — CPU package temperature sits in the low-to-mid 40s–50s °C (nowhere near the 105 °C throttle point), and the discrete GPU is confirmed idling correctly at its lowest power state. There's no thermal justification for the fans running this much.

Diagnosis (via lm-sensors and the dell-smm-hwmon/i8k kernel driver):

1. sensors shows both pwm1 and pwm2 on the dell_smm device explicitly flagged MANUAL CONTROL, not automatic:

   dell_smm-virtual-0
   fan1: 1987 RPM  (max 4200 RPM)
   fan2: 1987 RPM  (max 4200 RPM)
   pwm1: 64%  MANUAL CONTROL
   pwm2: 64%  MANUAL CONTROL

2. Confirmed via sysfs directly:

   cat /sys/class/hwmon/hwmon6/pwm1_enable   →  1
   cat /sys/class/hwmon/hwmon6/pwm2_enable   →  1

(per the standard Linux hwmon convention, 1 = manual, 2 = automatic/BIOS-controlled)

3. Attempting to hand control back to the BIOS fails outltr" tabindex="0">
    

      echo 2 | sudo tee /sys/class/hwmon/hwmon6/pwm1_enable
      tee: /sys/class/hwmon/hwmon6/pwm1_enable: Invalid argument

   The firmware is rejecting the standard SMM call this driver sends to re-enable automatic control.

   4. modinfo dell_smm_hwmon shows this driver's DMI whitelist (XPS, Precision, Latitude, Inspiron, OptiPlex, Vostro, Studio, and a few specific model codes) does not include "MC16250" or any Pro Max identifier. The driver appears to be binding through Dell's generic WMI interface GUID rather than a verified per-model entry — which likely explains why fan reading works but fan mode switching doesn't.
   5. The manual-mode PWM value also doesn't behave as a simple linear duty cycle: lowering the raw value (128→80 out of 0–255) made both fans run faster (2338/2368 RPM), not slower, and reverting to 128 restored the original speed. So this isn't just "no automatic mode" — the manual interface itself doesn't map predictably on this platform either.
   6. Ruled out software/configuration as the cause: this is a stock Ubuntu 26.04 install with no custom fan-control utilities, and stopping thermald entirely had no effect on the manual-mode state. Also consistent with the MC14250 thread's own finding that the behavior persists even from a Live USB boot.

   I hope you find this information useful for troubleshooting purposes, and hopefully get a fix soon.

    

   Thanks!