GF32.33-P-3400RT Rear Axle Level Control System Control Unit, Component Description

GF32.33-P-3400RT Rear axle level control system control unit, component description
- except CODE (489) Airmatic (air suspension with level adjustment and adaptive damping system ADS)
- up to model year 08

Component Identification:

Location
The rear axle level control system control unit is located in the floor assembly under the right front seat.

The rear axle level control system control unit has the following tasks:

Controlling
^ AIRmatic compressor unit (A9/1)
^ AIRmatic pressure reduction valve (A9/1y1)
^ Electronic rear axle level control valve unit(Y36/8)

Reading switches, pickups and sensors
^ Left rear level sensor (B22/7)
^ Right rear level sensor (B22/10)

Reading in the following discreet signals
^ Left rear level sensor
^ Right rear level sensor
^ Wake-up signal
^ Tml. 30
^ Circuit 31
^ Circuit 87

Discrete outputs
^ AIRmatic compressor unit
^ AIRmatic pressure reduction valve
^ Electronic rear axle level control valve unit

Reading in the following CAN-C messages
^ Vehicle speed
^ Steering wheel angle
^ Outside air temperature
^ Air pressure
^ Door status
^ Rear-end door status
^ Transmitter key (A8/1) status

Switching the following relays
^ Air spring compressor relay (F58kG)

Safety circuit
After switching on and during operation the rear axle level control system control unit monitors all the important components of the electronic rear axle level control system. The task of the safety circuit is to detect, faulty signals from the sensors, faults in the rear axle level control system control unit and in the electric line system. If a fault is detected, depending on the fault the system is only partially switched off and is displayed to the driver by the multifunction display (A1p13) in the instrument cluster (A1). In addition a fault code is stored is stored in the rear axle level control system control unit. The aim is always to maintain the adjusted vehicle level.

The safety circuit also constantly monitors the battery voltage. If the voltage of 9.0 V is dropped below or 16.5 V is exceeded the system is likewise switched off until the voltage is in the specified range again.

Lock position
If a relief of load on the rear wheels is detected by the rear axle level control system control unit when the vehicle is stationary, then the air supply to the air spring bellows is shut off via the electronic rear axle level control valve unit. The vehicle therefore remains at the current level. This is essential, for example, when changing a wheel or during repair work (lifting platform).