The engine smoothness control facility balances out the speed fluctuations of the individual cylinders caused by different injection quantities and degrees of cylinder efficiency. This is achieved by rapid application of controlled corrected injection quantities for each cylinder.
The control is active within a certain engine speed and injection volume range:
The DDE also monitors the correction volumes at injection volumes of above 17 mm^3/stroke/cylinder. Fault codes 1612 and 1613 "Smooth running controller" are stored if a correction volume exceeds 7.5 mm^3/stroke/cylinder (positive or negative). As a result, the converter lockup clutch in the automatic transmission is released to avoid damage to the drive train attributed to torque peaks.