NVPM WARN: fan mode is not set!

Any idea what this means or how to set it ?

The “help” from “nvpmodel -h” is equally gnomic, suggesting “nvpmodel -d fan_mode” with no further information …

I’m concerned that my fan may be being ignored by the kernel, though it does work (jetson_clocks spins it up).

Thanks for any insights,


hello dmbkaavn,

assume you had customize carrier board to mount a fan.
could you please share the environment setups, which JetPack release you’re working with.
please also share the details message about the nvpmodel.

No, standard nano developer kit, fan screws onto tje heatsink.
Npvmodel is MAXN (m=0)

hello dmbkaavn,

according to https://developer.nvidia.com/embedded/jetson-nano-developer-kit, there’s only heatsink on Nano developer kit.

Check out the fan mounting holes on the top of that heatsink next time you pass one and don’t forget the power and PWM outputs labelled “J15 - Fan header” on the developer guide at the link you posted. That’s where the … erm … fan plugs into the board.

hello dmbkaavn,

jetson_clock script file toggle the fan via sysnodes, which control pin J15.
for example,


may I also know what’s your hardware device part-number?
there’s supported components list for your reference, please check Jetson Nano Supported Component List.

Anyone got other ideas on where I might find documentation for this error, or the source code of npvmodel ?

Even documentation on how the kernel control is supposed to work would be useful.

It may be that the kernel doesn’t control the Nano temperature at all - I see some people have written code to monitor the temperature and switch the fan on/off, though this seems like a strange omission if so.


Is there a script that dynamically adapts the fan’s PWM depending on the measured temperature?

hello amdamdes,

please check similar discussion thread, Topic 1063982.
you may use the tachometer for measuring and also set the fan target rpm.

OK, so I think (?) we’ve established that the Jetpack kernel does not include any logic for automatically controlling the temperature by using the fan, and that there is no existing script to do this out-of-the-box.

Can we get back to my original question please ? What does “NVPM WARN: fan mode is not set!” mean, and what should I do to set the “fan mode”, whatever that is ?

Jerry - if you don’t know, please just say “I don’t know” rather than steering the discussion down unrelated or simply incorrect topics.



hello dmbkaavn,

fan mode is currently defined only for Xavier platforms.

That’s very helpful, thanks Jerry.

I’ll ignore the error message on the Nano in that case.


I found this automatic fan control solution here in the forum:


It’s the perfect solution for me.
Extremely easy to install, configurable and starts up automatically.

Thanks, I’ve installed that and it does work very nicely.