Pneumatic Level Control System
Pneumatic Level Control System
=> [ Air Lines Overview ]
=> [ Air Supply Unit Assembly Overview ] (engine codes BVJ, BFM, BGK).
=> [ Air Supply Unit Assembly Overview ] (engine codes BSM,BSB).
Air Lines Overview
1 Air Supply Unit
2 Right Front Air Spring Damper
3 "Green" Air Line
• From the solenoid valve block to the right front air spring damper.
• Air line servicing, refer to => [ Air Line, Servicing ] Pneumatic Level Control System.
• Connecting piece replacing, refer to => [ Connector Piece, Replacing ] Pneumatic Level Control System.
4 Rear Right Air Spring Damper
5 "Blue" Air Line
• From the solenoid valve block to the right rear air spring damper.
• Air line routing in the interior.
• Air line servicing, refer to => [ Air Line, Servicing ] Pneumatic Level Control System.
• Connecting piece replacing, refer to => [ Connector Piece, Replacing ] Pneumatic Level Control System.
6 "Black" Air Line
• From the solenoid valve block to the left rear air spring damper.
• Air line routing in the interior.
• Air line servicing, refer to => [ Air Line, Servicing ] Pneumatic Level Control System.
• Connecting piece replacing, refer to => [ Connector Piece, Replacing ] Pneumatic Level Control System.
7 Pressure Reservoir
8 "Purple" Air Line
• From the solenoid valve block to the pressure reservoir.
• Air line routing in the interior.
• Air line servicing, refer to => [ Air Line, Servicing ] Pneumatic Level Control System.
• Connecting piece replacing, refer to => [ Connector Piece, Replacing ] Pneumatic Level Control System.
9 Left Rear Air Spring Damper
10 Solenoid Valve Block
11 "Red" Air Line
• From the solenoid valve block to the left front air spring damper.
• Air line servicing, refer to => [ Air Line, Servicing ] Pneumatic Level Control System.
• Connecting piece replacing, refer to => [ Connector Piece, Replacing ] Pneumatic Level Control System.
12 "Brown" Air Line
• From the air supply unit to the solenoid valve block.
• Different versions
• Air line servicing, refer to => [ Air Line, Servicing ] Pneumatic Level Control System.
• Connecting piece replacing, refer to => [ Connector Piece, Replacing ] Pneumatic Level Control System.
13 Air Intake Line
14 Left Front Air Spring Damper
Solenoid Valve Block, Line Arrangement
Air lines are color-coded:
1. "Blue" air line to the right rear air spring damper
2. "Black" air line to the left rear air spring damper
3. "Green" air line to the right front air spring damper
4. "Brown" air line to the air supply unit
5. "Red" air line to the left front air spring damper
6. "Purple" air line to the pressure reservoir
Brown Air Line to Air Supply Unit
The "brown" air line - 1 - is located on the right side of the air supply unit.
It leads to the left front wheel housing with the air intake line - 2 -.
Different versions
Brown Air Line to the Solenoid Valve Block, Routing
The illustration shows the left front wheel housing without the suspension and engine.
1. "Brown" air line, note the different versions
2. Air intake line
Air Lines to Solenoid Valve Block, Routing
Line routing - 1 through 6 - on the solenoid valve block.
7 Solenoid valve block
8 Line grommet to the interior
For the air line to the left/right rear air spring dampers and the pressure reservoir
Green Air Line to the Right Front Air Spring Damper, Routing
The "green" air line - 2 - runs along the engine compartment/interior noise insulation - 1 - from the solenoid valve block to the air spring damper.
Red Air Line to the Left Front Air Spring Damper, Routing
1. "Red" air line
2. Protective hose
The "red" air line - 1 - runs along the engine compartment/interior noise insulation - 2 - from the solenoid valve block to the air spring damper.
Routing Air Lines in the Interior
The air lines are located in the front wire channel - 1 - and rear wire channel - 2 - on the left side of the vehicle.
Black and Purple Air Lines to the Left Rear Air Spring Damper and Pressure Reservoir, Routing
The "black" and "purple" air lines run along the left side of the luggage compartment to the wire channel in the interior.
1. "Purple" air line to the pressure reservoir
2. "Black" air line to the left rear air spring damper
3. "Blue" air line to the right rear air spring damper
4. Left rear air spring shock absorber
5. Pressure reservoir
Blue Air Line to the Right Rear Air Spring Damper, Routing
The "blue" air line runs along the right side of the luggage compartment to the rear bench seat, along the seat and to the wire channel in the interior.
1. "Blue" air line to the right rear air spring damper
2. Rear right air spring damper
Air Supply Unit Assembly Overview
1 Air Supply Unit
• Removing and installing, refer to => [ Air Supply Unit ] Pneumatic Level Control System
2 Spring Clamp
3 Muffler
• Component location: In the left wheel well.
4 Air Filter
• Component location: Left A-pillar above the solenoid valve block.
5 Bracket
6 Washer
7 Bolt, 20 Nm
8 Bolt, 4 Nm
9 Connector Piece, 2 Nm
• Only remove if the vehicle is raised and the air spring damper is unloaded (otherwise, there is a risk of injury from lowering vehicle).
• Replace the air line if there are leaks, refer to => [ Air Line, Servicing ] Pneumatic Level Control System.
• Clean connections before loosening.
• Air escapes when connections are loosened.
• Protect threaded connection from dirt.
10 Air Line
• Between the solenoid valve block and air supply unit.
• Replace the air line if there are leaks, refer to => [ Air Line, Servicing ] Pneumatic Level Control System.
11 Intake Hose Connecting Piece
12 Rubber Bushing
13 Spring
14 Sleeve
15 Self Locking Nut, 4 Nm
• Always replace after removal.
16 Connector
• For the level control pump temperature sensor (G290)
• The level control pump temperature sensor is installed in the air supply unit. It cannot be replaced.
17 Connector
• For the exhaust valve.
• The exhaust valve is installed in the air supply unit. It cannot be replaced.
18 Connector
• To the engine connection
Connector System
- The lines are routed correctly when only one of the markings - arrow - is visible.
• Loosen the connecting piece to remove the air line.
• Remove the protective transport caps from the air lines after routing them and right before making the connection.
• The connecting piece can be replaced if it leaks, refer to => [ Connector Piece, Replacing ] Pneumatic Level Control System.
• Air line replacing, refer to => [ Air Line, Servicing ] Pneumatic Level Control System.
Air Supply Unit Assembly Overview
1 Air Supply Unit
• Can only be replaced as a unit.
• Removing and installing, refer to => [ Air Supply Unit ] Pneumatic Level Control System.
2 Air Intake Hose
• From the muffler in the left wheel housing to the air supply unit.
3 Spring Clamp
• Remove and install with spring type clip pliers (VAS 5024A).
4 Bolt, 4 Nm
5 Washer
6 Rubber Bushing
• Always replace.
7 Spring
• Always replace.
8 Sleeve
9 Bracket
• Remove and install with the air supply unit.
10 Washer
11 Bolt, 20 Nm
12 Retainer Plate
• For the three connectors.
13 Bolt, 20 Nm
14 Clip
• For securing the connector to the retaining plate.
15 Bolt, 20 Nm
16 Connector Piece, 2 Nm
• Only remove if the vehicle is raised and the air spring damper is unloaded (otherwise, there is a risk of injury from lowering vehicle).
• Replace the air line if there are leaks. Refer to => [ Air Line, Servicing ] Pneumatic Level Control System.
• Clean connections before loosening.
• Air escapes when connections are loosened.
• Protect threaded connection from dirt.
Connector System
- The lines are routed correctly when only one of the markings - arrow - is visible.
• Loosen the connecting piece to remove the air line.
• Remove the protective transport caps from the air lines after routing them and right before making the connection.
• The connecting piece can be replaced if it leaks, refer to => [ Connector Piece, Replacing ] Pneumatic Level Control System.
• Air line replacing, refer to => [ Air Line, Servicing ] Pneumatic Level Control System.