D4F
D4F, and 740 or 742 or 764

D4F, and 784

K4J or K4M
Diagram of the air inlet circuit

K9K
K9K, and 764 or 772

K9K, and 766

K9K, and 768

K9K, and 750

K9K, and 752

M4R
Air inlet circuit

F4R

I - AT LOW SPEED
The soundproofing unit control solenoid valve (6) controls the soundproofing unit valve, which is in the closed position. Air enters only via the main air inlet (1).
II - AT HIGH SPEED
The soundproofing unit control solenoid valve (6) no longer controls the soundproofing unit valve, which is in the open position. Air enters via the main air inlet (1) and the soundproofing unit air inlet (4) at a ratio of 60% for the main air inlet and 40% for the soundproofing unit air inlet.
Note: In rest position the soundproofing unit valve is open; if the control circuit is not correctly sealed, the valve will be in the rest position.
Air resonator: Removal - Refitting
Air filter: Removal - Refitting
Air filter unit: Removal - Refitting
Driving
Your comfort