pwmconfig: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/sbin/pwmconfig - from package: lm_sensors

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/pwmconfig - from package: fancontrol

You may install the required package with command apt-get install {package}

Error in other languages:
pwmconfig: bevel nie gevind nie
pwmconfig: comandă negăsită
pwmconfig: comando não encontrado
pwmconfig: commande introuvable
pwmconfig: command not found
pwmconfig: käsku ei ole
pwmconfig: không tìm thấy lệnh
pwmconfig: komanda nerasta
pwmconfig: Kommando nicht gefunden.
pwmconfig: kommandot finns inte
pwmconfig: komut yok
pwmconfig: nie znaleziono polecenia
pwmconfig: níor aimsíodh an t-ordú
pwmconfig: no se encontró la orden
pwmconfig: no s'ha trobat l'ordre
pwmconfig: opdracht niet gevonden
pwmconfig: parancs nem található
pwmconfig: perintah tidak ditemukan
pwmconfig: príkaz nenájdený
pwmconfig: příkaz nenalezen
pwmconfig: команда не найдена
pwmconfig: командата не е открита
pwmconfig: 命令找不到
pwmconfig: コマンドが見つかりません