ML Fuel Gauge Fault

[Andrew D]

I'm in need of some advice from you experienced Merc types.

An ML belonging to a friend of mine has started giving erroneous readings on the fuel gauge. In some cases it reads empty even when it's been filled, but most of the time it just reads halfway.

Is this a common problem (i.e. design flaw) and what is the likely damage for repair at the main stealer?

[sneijder]

There's a problem with the way the fuel tank sender talks to the ECU. It'll need plugging in at your local dealer to see if it needs either a new tank sender or instrument cluster. The sender is part of the pump at around £230 + VAT, and the cluster (less common) IRO £370 + VAT.