GF32.33-D-2010H Electronic Level Control (ELC (ENR)) Special Tasks Function

GF32.33-D-2010H Electronic Level Control (ELC [ENR]) Special Tasks Function


- with CODE (CE2) Rear air suspension

Function requirements

^ Circuit 30
^ Circuit 15 ON
^ Model 639: Vehicle speed < 2 km/h
^ Model 906: Vehicle speed < 10 km/h
^ No overvoltage or undervoltage

Overvoltage present when the voltage is > 16.2 V.

Undervoltage is present when voltage is < 9 V.

General

The "electronic level control (ELC [ENR]) special tasks" function is made up of the following subfunctions:
^ Curb recognition
^ Control suspension when foot brake engaged

Curb recognition

To prevent a vehicle that is parked on one side of the curb from trying to stabilize, the left rear level sensor (B22/7) and right rear level sensor (B22/10) measure the level states.

The electronic level-control control unit (N97) (for model 639 (N51/3)) evaluates the two level states.

If the difference between the two level states is more than 30 mm, the electronic level control system suppresses a control intervention and rear axle level control does not take place. Only after the difference between the two level states is < 30 mm, does level control of the vehicle's rear axle take place. Any change in the status of circuit 15 in the meantime does not influence the operating mode.

Following repeated raising or lowering of the vehicle rear axle, the level control compressor (A9/1) is automatically deactivated in order to protect the ELC system.

Control suspension when foot brake engaged

Function requirements

^ Vehicle speed <2 km/h
^ Foot brake actuated

The position of the pivot point will alter the wheelbase during compression and rebound procedures. This will result in tensioning of the suspension. If the foot brake is engaged, the vehicle's rear axle level is raised or lowered for t = 4 s only, to prevent any tensioning and any relieving of the suspension after releasing the foot brake.

If the vehicle's rear axle level drops below a specific value, the vehicle will then touch down on the additional rubber spring integrated into each air spring bellows. This then restricts the suspension comfort.