The instrument cluster on the Mercedes W211 has been known to fail. Unfortunately, when this happens, there is no simple way to repair the cluster, which comes as a single unit. It is difficult to disassemble and even more difficult to reassemble properly. The easiest solution to the problem of a malfunctioning instrument cluster is to replace it. You can purchase a replacement instrument cluster directly from Mercedes-Benz or from your local Mercedes-Benz dealer. Installing a new instrument cluster is fairly simple and you should takes you less than five minutes to perform.
Turn the W211's engine off and adjust the vehicle's steering wheel so that it is at its lowest point. This will make it easier to remove the instrument cluster.
Push the removal tool in through the bottom corner of the W211's instrument cluster and pull it outward. The instrument cluster should pop out easily with little force. If it does not, try pulling the cluster out at a different angle. Repeat on the opposite side of the cluster.
Remove the two electrical harnesses at the rear of the cluster. Pull the cluster out of the W211.
Connect the two harnesses to the replacement cluster. Position the cluster in the dashboard and snap it into place. Adjust the steering wheel to its original position.