PeachParts Mercedes-Benz Forum - What does code 17 mean???? HELP

Low V condition is very possible, but if that seems fine....My first question on that chassis would be... "How is your wire harness? "

...and if that is cool , then the best thing for me to do here is probably to give you some insight of how CAN Data-Bus works on this chassis... [ not to be confused w/later CAN Systems] ...System understandings often make diagnosis easier, and this info will also make it to the Archieves at the same time..

That chassis has a simple , parallel, 2 wire buss connecting the N/59 emmissions module to both the HFM/SFI module [ N3/4] and EA/CC/ISC module [N 4/3 or N 4/1] .. This is for data Interchange between modules [ they talk to one another.. with Message being outgoing info, and Reception is incoming]. So, an info interchange fault code can be caused by an open circuit on a section of the data buss line or a poor connection at the plugs/connectors of the modules. It can also be the CAN Element circuit in one of the modules.
A DMM and the schematic can track down the circuit using the ohms scale.
All the connecting wires from/to each module are the green and white.
You can start with ohming the N/59 Element at pins L and H at that module [ the two wide pins] You are looking for 55-65 ohms.
The HFM and the CC/ISC should both be 115-125 ohms. Those will be pins L/H for HFM and pins 44/45 for EA.
If these modules ohm spec. check out , it is reasonable to assume they are in working order and the problem lies in the modules connecting wiring . Again , ohm meter and you are looking for continuity [ trace ohms ] between connectors at the modules.
A trick you can use [ you prob already know] is one can check cont. of a simple 2 wire feed circuit by bridging the opposite end of that line ..then you can ohm the line as a complete circuit from the testing end [ in other words, you now have created a complete loop by shorting the other end together and you are testing the integrity of that complete loop from it's origin.. any OPEN of that line will show as no cont. and good cont. will verify a completion of both those wires inter-connecting those two modules. Basically, just a tracing the circuit thing. Much easier than running wires between modules and back to the DMM.
You may also want to go to the other modules and get any existing codes..That can be done by making a homemade led/SW tool and the procedure is the same as you have done on the DM module.
Here is that info and codes for your chassis.

http://www.peachparts.com/shopforum/tech-help/107630-e320-16-pin-dtc-charts-inc-pin-8-pin-14-a.html

If there are CAN codes on those modules [ pins 8 and 14] , then you may want to clear all codes and retry until the code 17 re-apperars on the Emmissions module DM. It may just be a fluke code and not come back, but if it does , then the above DMM tracing info will get you to the cause.
If you have the CD, go to Schematic "Can Data Bus" and you will see how the 3 modules are wired up to the DM/N-59 with the two green and white wires , along with the connector plugs..it is pretty simple once you see it.
There is also a 3 wire CAN connector plug [X-63/1 ] between the HFM and the N59 modules..that could present a good possible for a poor Buss connection. [ only terminal 1 and 2 are used on that plug]

Maybe someone can post that schematic up. That will be Schematic " Can Data Bus-124. 00-C. 1/2-4. "
If you can't find the modules ,use the search feature .. that info is all in there.