Access to Diagnostic OBD II Module on 96 c280 - PeachParts Mercedes-Benz Forum

Martineau Gauda · #1 05-30-2008, 09:56 AM

Hi, I need to back probe some signals and voltages on the OBD II Diagnostic Module with Auto Multimeter.

It is designated as "N59/1" per Mercedes service data. This is the diag module where the signals come in and not the under dash OBD II connector used to plug in the readers for DTC. The O2 sensor input signals are available at this connection.

I believe the module is located in the cabin, but need to know where to look. Is the connector pins accessible without a special breakout adapter?

Thanks

Arthur Dalton · #2 05-30-2008, 10:01 AM

02 sensors plug is under the passengers side rug.

Martineau Gauda · #3 05-30-2008, 10:17 AM

Thanks that information is useful, but I still would like to access the OBD2 diag module itself as there are many other system tests specified by Mercedes, and Alldata that one can do with multimeter using this connector.

Thanks

Arthur Dalton · #4 05-30-2008, 11:58 AM

You mean the 38 pin plug under the hood.

Martineau Gauda · #5 05-30-2008, 03:26 PM

No not the 38 pin connector in the engine compartment. There is another unit, the OBDll Diagnostic Module that processes the signals for the OBDll connector. Both Mercedes service manuals and Alldata show procedures for testing at that point to diagnose specific DTC's with automotive type multimeter. Lots of valuable tests are shown with nominal range values and suggested actions. The connector is designated as N59/1.

Thanks

Arthur Dalton · #6 05-30-2008, 03:33 PM

N59/1 on that chassis is Digital DM/OBD2 Module, so I do not know how you are going to get any info from a MultiMeter.
If there were a connector . it would state X/- .... as X/27 or X/4, etc.