Stumped! Need direction
 

96 C280 with OBD2 code P0600 (Serial Comm Link Malfunction). Is this an automatic module replacement or is there a potential wiring (grounding, short, etc) issue. I'm not sure which module is not being identified via CAN. Any direction would help. TIA

I did some research on that code, I found both Serial Comm Link Malfunction and Auto Trans Communication Link Malfunction.

No suspicious Activity, but...
 

DANWATT, thanks for the assistance! I'll direct my focus toward the TCM link to the controller.

IS that the only code in all of the linked systems?

Those systems include ABS(traction), fuel, electronic accelerator, & diagnostic module OR are reading only OBD2??

McLean Auto Imports (Virginia)--Beware of this con!
 

I hope that I'm not stepping on any toes here, but I must vent! Beware of imposters that "claim" they "know" MBs. I've been too busy to handle routine maintenance, so the the Ms. took the car to the above shop for oil service. She came away with "exciting" news that the "auxiliary fan belt" was broken. And that the CEL had come on (because of the fan belt service, right!). I do the serp belt myself (when I've got the time) and also the brakes, fluids (oil, trans, diff), and whatever else needs attention. So, when she said this mechanic (Michael) told her that the aux fan belt was broken (220 $ to repair) I knew that I was up against an ethical imposter. The AC fans are ALL electric, yet he claimed that (when I called him) there's a small belt in there. I asked him what he did to set off the CEL, he hung up on me. So, I was left to troubleshoot through trial and error. That's when I called on the experts, here. Turns out that he wanted to line up future business by not securing the lever lockdown on the N3/4 brain. I went to check CAN resistances and lo and behold it was not seated and thus the code. All is well with the car now, but please check before taking your car to a vendor. And if you're there just for oil service, make sure the vendor knows that you're not interested in any other repair service. There's an honest way to make a living, and some choose not to pursue that.

My apologies for ranting, but to anyone in the DC-area, I'd avoid this guy's shop.