X5 4.8IS ilmajousitus

[Peruna]

Morot. Ostinpa tuollaisen bensanuukan suvin. Siina on napista ''ilmapusseilla'' saatyva sport-alusta. Osaako joku sanoa miten sen tulisi oikeasti toimia. Paikallaan ollessa laskee ja nousee moitteettomasti, mutta kun lahtee ajamaan esim. madallettuna niin palaa keskiasentoon hetken paasta. Sama tapahtuu korotettuna.

[BeamR]

Näyttäis siltä että kun nopeus nousee tarpeeksi suureksi, niin sekä korotus (off-road) että madallus (Access) deletoituu ja auto palaa normaaliin asentoon. eli sun panssarivaunu toimii ihan oikein.


2-axle air suspension
The 2-axle air suspension combines an automatic load compensation on the front and rear axles with the possibility for the driver to set various vehicle levels.

Brief description of components
Control unit
The control unit activates all the valves, the compressor and the LEDs. The control unit activates all the valves, the compressor and the LEDs. To achieve this, information from the height sensors, the button, the K bus and the CAN bus is used.

Air supply system
These elements are fitted beneath a sound-damping cover. These elements are fitted beneath a sound-damping cover.

Height sensors
The suspension travel at the individual wheels is determined by measuring the relative movement between the wheel and the body. Angle of rotation sensors are used to achieve this.

Rocker switch with LEDs
The driver has a rocker switch with up/down function, which can be used to change the height level. Three LEDs are located beside the rocker switch to indicate the current height level.

Accumulator/valve unit
The accumulator/valve unit is located behind the right-hand sill, beneath the underbody panelling. The accumulator/valve unit consists of: the solenoid valves, the pressure accumulator, the pressure accumulator sensor and the pressure accumulator valve.

Main functions

System function of 2-axle air suspension
The 2-axle air suspension automatically regulates load changes on the front and rear axles. In addition, the driver can set three different heights, for example to achieve greater ground clearance in off-road driving.
There are three different heights:
- Standard: normal driving height
- Off-road: increases compared to normal driving height
- Access: lowered in relation to standard, for entry/exit, loading/unloading
In every case, the current height is indicated by the corresponding, permanently lit LED. As soon as the driver specifies a new target height by pressing the button or a change is initiated automatically by a certain driving condition, the LED of the current level remains lit and the LED of the target level flashes. When the new level is reached, the LED of the last level goes out and the LED of the newly reached level lights up permanently.
A special case is advance selection of the Access level while driving: the Access LED flashes and the LED of the original level lights up permanently. However, this does not mean that adjustment has started. This only takes place when the corresponding speed threshold that permits the Access level is reached or the speed falls below this threshold.
As soon as the ignition is switched on (terminal 15), downward level changes requested by the driver are possible. Upward changes of the level - and thus filling of the accumulator - are only possible when the vehicle engine is running.
These functions are enabled by activation of a compressor and various valves in the air supply system and the accumulator unit.
The control unit receives information of the current height of the vehicle from four height sensors. The pressure in the pressure accumulator is also registered by a sensor. The evaluation of various signals on the CAN and K buses enables recognition of driving situations and activates corresponding adjustments.
The interface to the driver consists of a button and corresponding LEDs. The 2-axle air suspension control unit can also activate text messages in the text display of the instrument cluster. The system is activated by the front axle signal and can thus become active before the vehicle is started.

Service functions

Height calibration or offset by DIS/MoDiC
As is familiar from the 1-axle air suspension system, a height calibration must also be performed for the 2-axle air suspension under certain conditions, e.g. following replacement of a height sensor. All air suspensions can be lowered or raised individually. The required activations are performed using the corresponding routines in the diagnostic program for the 2-axle air suspension. When the vehicle has reached the correct height (see TIS for height values), the height offset is performed. In the case of the 2-axle air suspension system, the offset function is performed on an axle-by-axle basis, i.e. first on the front axle and then on the rear axle. Before the offset command is executed, the height should be rechecked.

Operational test after part replacement or repair
On the 2-axle air suspension, the function of the components concerned must be checked with the corresponding service function after repair or part replacement.

[BeamR]

ja kun nyt kerran sattui samaan syssyyn noita vikakuvauksia:

Vehicle inclination
There can be a wide variety of causes for a vehicle inclination. The causes usually lead to an entry in the fault memory of the control unit or to a CC message in the instrument cluster.

Causes for vehicle inclination
Sensor causes
Checking of the sensor system according to instructions in the adjacent diagnosis test module.

Mechanical causes
Sensor linkage (position, defective)
Sensor holder (position)
Securing clip of the sensor linkage (position)

Leaks as causes
Leak in the lines
Leak in the valve block
Leak on the spring strut

Electrical causes
Water in the connector (corroded pins): With this fault, a creeping inclination begins, as the signal slowly drifts away.
Short circuit in the 2-axle air suspension system (but this is normally stored by the control unit as a fault and detected via diagnosis).

System-specific causes
Opening a vehicle door during a change in the ride height (vehicle at a standstill) can cause a vehicle inclination.
Rapid forces being exerted from the outside (attaching a trailer, fast loading or unloading) can prevent regulation.
Tolerance bands with ignition on: +/-10 mm to height value from TIS. Note: In the case of the front axle, the mean value of both heights counts.
Tolerance bands with ignition off: +15 mm/-20 mm to height value from TIS. Note: In the case of the front axle, the mean value of both heights counts.
Temperature deactivation

[wta]

Siis onko tuo madallus (access) siis tarkoitettu ainoastaan autoon nousemista varten (sen helpottamiseksi) vai miksi madallus lähtee pois päältä kun nopeus kasvaa tarpeeksi? Luulis juuri, että madallus olisi parempi suuremmissa nopeuksissa...

[BeamR]

valistumaton arvaus: kun auton ajodynamiikka, alustan säädöt jne on tehty ja suunniteltu normaaliin ajoasentoon, niin ajaminen ala-asennossa muuttaa auton ajokäyttäytymistä, lisää renkaiden kulumista ja lyhentää nivelien ja puslien elinikää. Eli syy: turvallisuus ja kuluminen.

[BMWFW24]

Off-road: max nopeus 50km/h
Access: max nopeus 35km/h, voidaan kuitenkin aktivoida kun ajonopeus on alle 25km/h, pudottaa korkeutta 35mm vakiokorkeudesta.
Näin väittää Bentleyn manuaali...

[jrbeemer]

Off-road: max nopeus 50km/h
Access: max nopeus 35km/h, voidaan kuitenkin aktivoida kun ajonopeus on alle 25km/h, pudottaa korkeutta 35mm vakiokorkeudesta.
Näin väittää Bentleyn manuaali...

Pitänee kattoa manuaalista mutta muistelen accessin laskevan vaan puoltoista senttiä.

[Hebbu ///M3]

vahinko. meni mobile operalla väärään paikkaan.

[Peruna]

Kiitos kaikille vastauksista!