Control method for a compressed air supply system, control device and vehicle

A method for controlling a compressed air supply system for a vehicle wherein the compressed air supply system is assigned a control device in order to supply a compressed air consumer via a compressed air supply port and the compressed air supply system has a compressed air provider for providing compressed air at a compressed air port, a pneumatic main line which has an air dryer for drying compressed air and conducting same to the compressed air supply port in a filling direction, and a branch line which branches off from the pneumatic main line upstream of the air dryer in the filling direction and rejoins the pneumatic main line downstream of the air dryer in the filling direction, the method comprising:

• receiving, at the control device, a supply requirement of the compressed air consumer;
• activating, via the control device, the compressed air provider in order to provide compressed air at the compressed air port should the control device receive the supply requirement;
• determining, via the control device, a risk of freezing on a basis of at least one of information about a surrounding area and information about an operating state of the compressed air provider;
• activating, via the control device, a main-line switching valve in order to close off the pneumatic main line in a first operating mode should the risk of freezing be below a predefined limit value;
• and,
• conducting the compressed air through the branch line to the compressed air supply port in the filling direction in the first operating mode to supply the compressed air consumer.