Not enough water

Be aware that you should remove dishwasher's power cable before touching wires or making resistance measuring !!!
Check that the inlet valve get power. In case it does and no water
entering the tub, check with multi-meter for solenoid's resistance (disconnect first the wires to it),if no measurement result, you should replace the valve.
In case you have a measurement result, remove the solenoid from the valve and check that it's clean from any dirt.
In case there is no power to the inlet valve - check that the float switch works. This is usually a small switch attached to a float. The float (usually a cylindrical) located inside the dishwasher at the bottom. As the water level rises, the float rises too. When it reaches the certain height, the float activates its switch, which cuts the electricity to the water inlet valve. If the switch is defective (stuck in the disconnected position)it will prevent power from the inlet valve.
The switch is an On/Off switch and you can check it easily by a multi-metr.
Good luck !!

it is the pressure switch that controls the water level, it is also a switch connected to the motor,once the contact triggers so prematurely, your water level will not reach its designed level, or check the pressure.

Shut off the water valve to the dishwasher. Disconnect the water line at the dishwasher, place it into a bucket, and open the valve to check the water flow.

go to miele UK & download manual for g670. has instructions on how to check and adjust water level