BMW Lousy Idle
This bulletin applies to 2018 BMW 340I GT xDrive vehicles. The vehicle may run rough or hesitate when accelerating from a stationary position and fault code FC 21A02D (combustion control: valve lift correction when at idle) may be stored in DME fault memory.
The cause may be a software error in the DME (digital motor electronics). The correction involves updating the vehicle software using ISTA 4.
1. If other faults are stored, diagnose and repair before the update. Do not replace any parts to specifically address DME FC 21A02D.
2. Program the vehicle using ISTA 4.10.20 or higher to integration level 18-03-520 or higher.