Hydraktiv 3+

[C5entusiast]

my car runs in stiff mode at the back sometimes where it also rises after driving over speed bumps. Has changed the regulator valve and height sensor. Anyone have a solution?

[GiveMeABreak]

If the height sensor was not put back correctly in the exact position (and I mean if the clamp that holds the sensor on the rear axle was moved) then this can result in incorrect height data being sent to the suspension ECU in the BHI.

The only other thing I can think of is the Hydraulic block or there is air in the system.

Try bleeding the system:

• Start the engine.
• Wait for the vehicle height to stabilise.
• Put the vehicle in the "high" position.
• Lower the vehicle to the low position.
• Turn the steering from lock to lock in each direction several times slowly, but do not hold the steering at each lock.
• Stop the engine.
• Check the LDS fluid level.

Repeat if necessary.