Did it go left or right........ or straight ahead? It's usually the driver's interaction with the steering wheel that causes it.
Ford focus with 2.0 eng.zetec
Mecron ATF is used for the Ford Focus.
According to the 2003 Ford Focus Owner Guide : ( Motorcraft MERCON automatic transmission fluid is used as the power steering fluid )
the power steering reservoir is located next to coolant expansion tank in the engine compartment.
By getting a Focus
slipping power steering belt , worn or loose .
The power steering fluid reservoir is by the firewall towards the passenger side of the engine
their is no power steering cap on the 2012,because it is an electrical belt driven unit.
On a Ford Focus, the power steering sensor is typically located on or near the power steering pump or within the steering column, depending on the model year. For electric power steering systems, the sensor may be integrated into the steering rack or motor assembly. It's best to consult the vehicle's service manual or a repair guide for the exact location specific to your model year.
Power steering should never go down unless there is a leak found in the system. Therefore, you generally would not need to top up your brake fluid on a ford Focus.
http://www.2carpros.com/car_repair_information/year/2004/make/ford/model/focus/2004_ford_focus_drive_belt_routing_diagram.htm
The power steering reservoir is at the front of the engine compartment just to the left of your engine oil dipstick when you are looking from the front of the vehicle