2010.5 Citroen DS4 DAG air filter

Ventilation
Air intake
The air circulating in the passenger compartment is filtered and originates either from the outside via the grille located at the base of the windscreen or from the inside in air recirculation mode.
Air treatment
The incoming air follows various routes depending on the controls selected by the driver: - direct arrival in the passenger compar tment (air intake), - passage through a heating circuit (heating), - passage through a cooling circuit (air conditioning).
Control panel
The controls of this system are grouped together on control panel A on the centre console.
Air distribution
1. Windscreen demisting-defrosting vents. 2. Front side window demisting-defrosting vents. 3. Side adjustable air vents.
4. Central adjustable air vents. 5. Air outlets to the front footwells. 6. Air nozzles to the front footwells. 7. Air outlets to the rear footwells.

77Comfort
Recommendations for ventilation and air con ditioning
If after an extended stop in sunshine, the interior temperature is very high, first ventilate the passenger compar tment for a few moments.
Put the air flow control at a setting high enough to quickly change the air in the passenger compar tment. The air conditioning system does not contain chlorine and does not present any danger to the ozone layer.
In order for these systems to be fully effective, follow the operation and maintenance guidelines below:  To obtain an even air distribution, take care not to obstruct the exterior air intake grilles located at the base of the windscreen, the nozzles, the vents and the air outlets, as well as the air extractor located in the boot.  Do not cover the sunshine sensor, located on the d ashboard; this is used for regulation of the digital air conditioning system.  Operate the air conditioning system for at least 5 to 10 minutes, once or twice a month to keep it in per fect working order.  Ensure that the passenger compar tment filter is in g ood condition and have the filter elements replaced regularly (refer to the "Checks" secti on). We recommend the use of a combined passenger compa r tment filter. Thanks to its special active additive, it contributes to the purification of the air breathed by the occupants and the cleanliness of the passenger compar t ment (reduction of allergic symptoms, bad odours and greasy deposits).  To ensure correct operation of the air conditioning system, you are also advised to have it checked regularly as recommended in the Maintenanc e and Warranty Guide.
 If the system does not produce cold air, switch it off and contact a CITROËN dealer or a qualified workshop. When towing the maximum load on a steep gradient in high temperatures, switching off the
air conditioning increases the available engine power and so improves the towing ability.
The condensation created by the air conditioning results in a discharge of water under the vehicle which is per fectly normal.

227Checks
Petrol engines
The various caps and covers allow access for checking the levels of the various fluids and for replacing cer tain components.
1. Power steering reser voir. 2. Screenwash and headlamp wash reser voir. 3. Coolant reser voir. 4. Brake fluid reser voir. 5. Battery/Fuses. 6. Fusebox. 7. Air filter. 8. Engine oil dipstick. 9. Engine oil filler cap.

Diesel engines
The various caps and covers allow access for checking the levels of the various fluids, for replacing cer tain components and for priming the fuel system.
1. Power steering reser voir. 2. Screenwash and headlamp wash reser voir. 3. Coolant reser voir. 4. Brake fluid reser voir. 5. Battery/Fuses. 6. Fusebox. 7. Air filter. 8. Engine oil dipstick. 9. Engine oil filler cap. 10. Priming pump * . 11. Bleed screw * .
* According to engine.

Checks
Battery Air filter and passenger compartment filter
Oil filter
Unless other wise indicated, check these components in accordance with the Maintenance and Warranty Guide and according to your engine. Other wise, have them checked by a CITROËN dealer or a qualified workshop.
The battery does not require any maintenance. However, check that the terminals are clean and correctly tightened, par ticularly in summer and winter. When carrying out work on the battery, refer to the "Practical information" section for details of the precautions to be taken before disconnecting the battery and following its reconnection.
Refer to the Maintenance and Warranty Guide for details of the replacement inter vals for these components. Depending on the environment (e.g. dusty atmosphere) and the use of the vehicle (e.g. city driving), replace them twice as often if necessar y (refer to the "Engines" section). A clogged passenger compar tment filter may have an adverse effect on the per formance of the air conditioning system and generate undesirable odours.
Replace the oil filter each time the engine oil is changed.
Refer to the Maintenance and Warranty Guide for details of the replacement inter val for this component.
The presence of this label, in par ticular with the Stop & Star t system, indicates the use of a specific 12 V lead-acid battery with special technology and specification, for which the involvement of a CITROËN dealer or a qualified workshop is required when replacing or
disconnecting the battery. Failure to obser ve this recommendation may shor ten the life of the battery.