This is covered by a Service Campaign
In the latter part of 1999 M-B phased into production new style instrument clusters and three-finger contact fuel sending units (FSUs). The clusters use a pulsed power source to measure the sending unit's float position. Unfortunately, these new FSUs are adversely affected by poor Stateside fuel quality.
Complaints regarding fuel gauge accuracy in vehicles using these new components are being addressed by replacement of the FSUs (MY '00 W202 employs two) together with the instrument cluster.
This problem is not limited to C-class vehicles; also affected are CLK (208), E (210), S (220) and CL (215) class vehicles.