Asus P5KPL-CM - Manual (Page 24)

1-12 Chapter 1: Product introduction
3. Connect the CPU fan cable to the connector on the motherboard labeled
CPU_FAN.
Do not forget to connect the CPU fan connector! Hardware monitoring errors
can occur if you fail to plug this connector.
P5KPL-CM
R
P5KPL-CM CPU Fan Connector
GND
CPU FAN PWR
CPU FAN IN
CPU FAN PWM
CPU_FAN