Just bought a high mileage 2001 ML320.

The BAS-ASP-ETS and Check Engine lights are on and the courtesy lights do not work. Fuse 13 is good which protects courtesy lights and diagnostic computer. Evidently there is a disconnect at least to the lights. Any suggestions? Where is the computer located?

Also any suggestions on checking out this car with 231,000 miles on it? I understand that the timing chain has no service interval. What other items might require service? Thanks.

Try reading these posts it might assist:
ABS/ETS/ESP Lights coming on

Vehicle speed sensor 'A' code P0500 (BAS,ESP,ETS,ABS - lights)