I don't know what Freightliner uses, but many people use a Scangauge II. It is basically an OBDII scan tool, but seems to be capable of reading more of your Sprinter codes than many of the generic OBDII scan tools. The best prices I've seen for them seem to be when J.C. Whitney has a percentage off deal with free shipping. Other than that the prices seem pretty consistent.
From what I've learned the problem with OBDII scanners and the Sprinter is that diesel engines are not required to meet the OBDII protocols. They'll read some generic codes, but are not as specific with information as a DRBIII unit using the Sprinter specific card and cable.
A list of codes is here:
https://sprinter-source.com/forums/showthread.php?t=5369
I've had pretty good luck getting information from my 2004 just using my Actron CP9175 OBD2 Autoscanner.
Here's a reply they sent after I asked about compatibility with the Sprinter.
This is the answer from Actron.
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Dear Customer,
The CP9175 performs a global request for codes. Some diesel vehicles and vehicles over 8500 lbs GVWR are exempt from certain OBD II regulations and may require a tool with Enhanced capabilities. Unfortunately, we do not have Chrysler diesel or Mercedes specific (enhanced) support.
This vehicle is reporting this code as a response to a global request for DTC's. The best way to verify if the vehicle is reporting a true code is to try another tool and compare results or check with the manufacturer.
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Post is here:
https://sprinter-source.com/forums/showpost.php?p=40125&postcount=10
Maybe you know all this already....... Anyway, hope this does some good. AP/vic