Especially on a W210 with rudimentary OBDII, if you want a cheap scanner that you can throw in the glove box, try an Autel Maxiscan 300, they are about $16 on a****n.

Note that the W210 was the first MB with OBDII and it only has the legally required OBDII functions of that era, mainly the emissions related engine codes and a couple catchall transmission failure codes for the 722.6.

The modules on the W210 had their diagnosis leads brought to the 38 pin connector in the fuse/front SAM box by the brake booster. The only way to interrogate these modules is to use the HHT or Xentry via the 38 pin port. So don't waste your money on a higher dollar scanner thinking you can diagnose the ABS, SRS, etc via the OBDII port.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech