So I just bought an 04 CLK 500 convertible with 119k with some top issues(not functioning right but i just manually closed it for now), and I was under the assumption it needed a starter. The car sat for a little while but battery had a good charge like 12.2v, the key turns and all the lights come up along with some warnings to go to the workshop and the car can even be shifted out of part but no start I played with it checked all the features and its little issues within the interior and then tried it again and it cranked right up, I then was able to test drive it and see how everything was working and it drove great so I bought it(Didn't turned it off till I got the car home) So I ordered a starter and it just got in so I started doing some diagnostics to make sure that's what it was(I'm not familiar with the car, my only other MB is a 92 300D).. So I popped the hood and notice the cover for the fuse panel was not on and it was raining so chances are it got wet. So upon some google and forum searching I was lead to testing the purple wire so turned the key and no power.. I jumped power from the battery jumper lead and it turned over just fine but no start(key turned to on), so now I realize I'm Screwed, lol "ELECTRICAL ISSUES!!!!" something is cutting the car off but since the key lets me turn and shift out of park I'm assuming its not an EIS issue but... I don't know... So here's where I'm at now. The car also has top issues but I have not messed with it yet, top wasn't down all the way when I got it so I popped the pressure valves in the trunk and cycled it manually (fluid level was low, I have not started messing with that system yet)..
Any Ideas for this no start, I currently has the battery disconnect switch off to let it sit overnight and see if anything changes after a couple ours left to reset everything
These are the codes my scan tool was able to pull(Autel AL619) though I have since cleared the and still no start..

P0600 $10 Serial Communication link
C1022 CAN communication with engine system faulty
C1024 CAN communication with engine system faulty
C1029 Fault in CAN communication with unit n73 (EIS [EZS] Control unit)
c1035 MIL ON&Stored& Current The signal from compnent N49 (Steering Angle Sensor) is Faulty
C1038 Engine Control Module not identified or incorrect control module

I'm currently contemplating getting the iCarsoft MBII or possibly the more expensive multi-car unit (if it too will give me access to all the MB modules) or possibly the clone STAR diagnostic stuff if its available

It seems that you are more inclined to pursue the solution yourself rather than having it analyzed at a reputable shop. In hindsight it would have been beneficial to pay to have the car inspected before buying it.

I agree those are a lot of communication/potential electrical errors. Unless the prior owner was just a complete bone head however, they are probably from a single source. The last error regarding the ECU would be where I would start. Perhaps one of the gurus here can tell you if that is an err common to installing an ECU not linked to the car. The SAM would be my step 2 to investigate.

There is a starter relay but it would not generate all those comm errors. (I assume the ignition switch was in position 2 when you got the errors)

Hello. Was this problem ever resolved? I have similar problems on my 2004 CLK320: no start, C1022 and C1038 errors.

Thanks

Sounds like you have a faulty ECU, I don't think it will be easy to figure out the problem without an access to a good diagnostic tool (at lease iCarsoft MB II). Without it you could try to check ECU connectors. If you have an oscilloscope you can try to check CAN bus wires on the ECU connector.
If a diagnostic tool can read the ECU (your ECU is using k-line, not CAN bus for diagnostic) then it's probably just faulty wires.

Thanks for the reply. Yeah, I also thought most likely ECU problem. So I sent it in to SAI for testing/repair last week. And they just called today and said it tested good! And they are sending it back. Thus my starting to research threads for those two errors. I'll see what it does when it arrives back. But I am not expecting any change.

You could try to measure resistance between CAN-H and CAN-L on the ECU connector https://miro.medium.com/v2/resize:fi...5ezMW1O8o1.jpg
Resistance should be around 60 Ohm, but be sure that the car is completely off, since you removed your ECU I'd image that you already disconnected your batter . Otherwise not "sleeping" modules could mess-up reading.

Thanks for the diagram! Got ECU back from SAI. The resistance between the CAN-L and CAN-H pins on the bench is about 100-120 ohms. Not sure my cheap multimeter is super accurate. At least it isn't an order of magnitude off! Haven't put it in the car yet to try testing at the OBD2 connector and see if those C1022 and C1038 errors are still there because it is crappy weather outside. Maybe tomorrow.