So continuing my epic journey of hating this car but basically being stuck with it....

Did the spark plugs. Then the radiator immediately split on the same day. Was original.

replaced the radiator, its mounts, and the upper hose with OEM. Seemed to go well and good. BUT i now have the "coolant visit workshop" malfunction and I can't get rid of it. The system is bled out fine, no overheating, no low coolant. The fan now comes up with IGN at pos 2 with high speed and just stays on. My Autel scanner is picking up no codes at all.

I have read there may be an issue with an "adapter harness". Anyone do this with success? the service bullet mentions P2073(004) code along side the fan being on, but i dont seem to have any codes. Is the harness particularly expensive? I may attempt it if not. Calling my parts guy tomorrow about it.

Other options i read about where not going to happen (ecu replacement).

Please be aware of the head bolt problem as your CLK 63 has the M156 engine... Any white smoke through the exhaust?

i have a CLK55

You might check the water temp sensor. Also a STAR scanner will most likely pick up the fault. I would go over the entire area you worked on and look for anything that did not get plugged back in.

Agree with Insame1,
Also some CLK55 had an ECU glitch that ran the fans 100%. Some say the ECU must be replaced I disagree.
There is a fan control module under the drivers wheel well splash shield. It is worth investigating the condition of the wiring and connections.
I have read in 1 post in the forums some time ago that Jerry @ Eurocharged has programmed around the glitch if it is applicable.

Cheers, Gator

nothing is missed on install. I ordered the harness adapter per the service bullet since it was 50 dollars. I figure the only thing i mess with was the fan connection and if its brittle / known to fail to the point mercedes put a notice out on it, its worth a try. I will report back once it comes in.

I removed my inner wheel well splash shields today for bumper cover removal. (found no fan controller). Sorry if mis guided but I have been mis guided as well.
It is strange E bay lists the part and a reputable euro indy shop owner pointed me to the wheel well.

Oh Well well find it one of these days.

Cheers, Gator

the fan controller is actually on the shroud w/ the fan.

[robert stack voice] UPDATE! [/robert stack voice]

the adapter harness just take the stock plug, plugs that into the female end of a 12" harness. then the male end goes into the module on the fan shroud. What does that do for my problem? seemingly nothing. It did change from high to normal speed i think. Seems not as long, so i assume the harness somehow modulates the signal to step down the fan speed. But my problem persists.

Interestingly, the adapter has a spot on the shroud to clip to.

New plan. drive it and maybe it fixes itself.

So next step, trying to see if i have continuity between ecu and module. Dealer said "pin 39" on connector 5 at the ecu. well connector 5 is a 9 pin deal and I dont see any other pin number system.....Anyone have a more accurate layout?

so connector 3 has a pin 39 AND the color of the wire seems correct (green and blue). Just for kicks, i checked every single wire at the ecu for continuity and nothing showed to have it. I then reconnected it all and tried seeing what was at the connector with power. I got essentially 0 volts at the connector to the module.

Thus, it is looking like a wire break.

It does sound like just that. Hopefully it will be easy to fix.

so after some searching i found the broken wire! repaired it, and viola! fixed.

Booyah, Gald to hear you figured it out!