It is not uncommon for the second generation Mercedes E-Class to lose the power in its steering assistance due to a system failure occurring within the control unit. Although the mechanical steering will be maintained, it naturally takes far greater input from the driver. When this fault occurs, in addition to the greater physical effort required, a warning both visually displayed on the dashboard and audibly via a signal tone, will be obvious.
If the problem is not caused by a fault in the power steering control unit, there may well be no warning light or tone, which means that the issue is likely to be caused by faulty or worn steering parts.
Other known steering & suspension problems include excessive wear of the ball joints in the front suspension and the anti-roll bar bushes, which should therefore be checked at regular intervals. If replacement is required, FLG recommends that in common with all suspension component replacement and to maintain the most predictable handling characteristics of the vehicle, these items are replaced in pairs.