BMW Software Update
This bulletin applies to 2018 BMW 340i GT xDrive vehicles. The engine may run rough or hesitate when accelerating from a stationary position and DTC FC 21A02D ("combustion control” valve lift correction at idle) may be set in the DME fault memory.
The cause is a software error in the DME (digital motor electronics). Update the vehicle software using ISTA 4. 10.20 or higher to integration level 18-03-520 or higher.
Do not replace any parts to specifically address DME FC 21A02D.