Yes – to disable the LED while retaining function on the CM sensor, you have to use long mode programming.
Press and hold the button until the LED begins to flash. As soon as it begins to flash, press the button 20 times. The LED will then begin to blink its current setting – as soon as it does so, press the button twice. It will then flash the new setting – as soon as it starts flashing, press and hold the button until the LED begins to flash, then release the button and immediately press it 20 times.
If the programming is successful, the LED will flash twice, and then the LED will be disabled on the device.