idospots

I have a 1994 C280. Since the beginning of this year I have been unable to pull codes from my ODB II code reader. (BTW, the speedometer/odometer stopped working around the same time.) I've tried using other code readers in the port from various places, but they all give me error messages -- none of them will give me any codes. At this point I have to assume there is something wrong with the port internally, or elsewhere on my vehicle. Does anyone have any experience with this? Thanks in advance for your advice.

Plutoe

If you want my help post the VIN!!

idospots

WDBHA28E0RF108591

Plutoe

First, the IC check fuse 4 and 7 are they good!!

Second, regarding the 16 pin OBD diagnostic socket---what happens when you place the adapter in the 38 pin socket and use that socket can you read any faults---remember the the OBD reader will not be able to communicate with the non OBD chassis and transmission modules---for that you need the HHT tester built into DAS!!

idospots

Thanks for your response.

1. "First the IC..." I have no idea what "IC" means.
2. I checked fuse #4 and #7 and they are good.
3. I have never used an "adapter" with my 16 pin ODB scanner. We've only plugged 16 pin scanners directly in the 16 pin socket under the steering wheel.
4. When I plug in the scanner, I follow all the instructions, it does it's thing, and about a minute later, it tells me "Link Error!!" every time.

I'm not familiar with any other sockets for code readers, and I'm not clear on the last part of your message: "...the ODB reader will not be able to communicate with the non ODB chassis and trans modules. For that you need the HHT tester built into the DAS."

5. What does "HHT tester" and "DAS" mean?

To clarify further, my code reader and port used to work fine, then suddenly stopped. I took to Auto Zone and other places and let them try their code readers in the same 16 pin port. None of those worked either. All gave the same "Error Link" Message.

Plutoe

1. IC=instrument cluster
2. fuse 4 and 7 are the IC fuses
3.do a google search for the OBD 38pin adapter
4.use the 38pin socket(circular) located in the fuse and relay box
5.HHT=hand held tester is the MB diagnostic tool used to diagnose your car via the 38 pin connector

mrtylmz

Have you found the problem, I have the same problem on w202 C220 1994 it does not communicate with any scan tool and speedo and odo are not working

mrtylmz

I have solved the speedo and odometer problem but they have proved not to be related to diagnostic tool communication problem since communication problem still exists but I have tried with autocom and launch both did not work maybe original tool is required. Coming to the speedo and odometer problem it was because of aftermarket radio, the vss signal comes from abs module and it is shared between some modules so the radio grounds the signal causing odometer not to work