CITROEN 2005 C4-XSARA-XSARA PICASSO BERLINGO Owner's Manual page 451

CHECKING THE EFFICIENCY OF THE AIR CONDITIONING SYSTEM
Principal problem
Abnormal levels of pressure
Aircon circuit diagnosis table
Symptom
Low pressure and high pressure too high
Low pressure too high and high pressure too low
Low pressure too low and high pressure too high
too high
Low pressure and high pressure too low
445
Possible causes
Aircon pressure reducer defective
Duct clogged
Aircon compressor seal defective
Aircon evaporator sensor defective
Aircon pressure reducer jammed
Filtering and drying cartridge obstructed
Duct clogged
Duct clogged
Aircon pressure reducer jammed
Lack of aircon fluid in the aircon circuit
Aircon compressor defective