continued

The following WIS drawings complete the W216 fuse/relay information.

 

Excellent information, but...

I'm still unable to locate the fuse and relay for the intercooler (aka "charge air") pump. None of the fuse nor relay descriptions look anything like that.

I recently purchased a 2009 CL600 with a dead intercooler pump. I replaced it yesterday with a new Bosch "10" one, and of course want to TEST it before reattaching the inside right wheel cover and front underbelly cover, etc.

Thanks!,
Greg

 

Whoops, the "W216 N10-2 fuse assignments f115 - f152.pdf" document shows that fuse 116 is listed as "Charge air cooler circulation pump". Great. Though it's strange that it's in the trunk rather than the engine compartment?!

And I don't think it's ACTUALLY in the trunk on my CL600 (C216 body) but rather behind the rear armrest.

I would THINK that one of the relays on that same circuit board would control the pump. But the " W216 N10-2 relay assignments M - S.pdf" document doesn't have anything about "Charge air" nor "Intercooler" nor "M44" (the intercooler pump circuit). It shows that relay "S" is for the "Circulation pump relay" on my M275 engine, but I think that's the circulation pump for the cabin interior in "Rest" mode, not the intercooler pump.

Any help appreciated,
Greg

 

No, relay "Q" is the one listed as "Circulation pump relay". And given its close proximity to fuse 116 ("Charge air cooler circulation pump"), I'm guessing that "Q" is the proper relay for the intercooler pump.

But wouldn't you know it: of the seven relays on that circuit board, "Q" is the only one that is virtually IMPOSSIBLE to access with the circuit board in place. The very solid rectangular opening to the board (after removing the cover panel) hides about 1/2 of the relay tops at the back and about 1/2 of the relay tops at the side. And because "Q" is at the very corner of the board, it has 3/4 of its top surface hidden. Can't get the thinnest of fingers in there.

(Reminds me of working on an MG Midget years ago where you needed needle-nose pliers and/or very small hands for many repairs.)

The even more aggravating thing is that I also recently bought a Zurich ZR-Pro scanner from Habour Freight on sale. It has lots of capability for actuating various circuits, and 99% of the ones I've tested so far work as advertised. But of course the "M44" activation doesn't work ... seems to be a bug in the Zurich coding (I've reported it). Pressing the F3=ON button simply returns to the previous page without doing anything.

Well, I may just give up and put the car back together and take it out for a test drive, getting it onto turbo boost and hot for a while to see if I can get that intercooler pump running. I'll leave the bottom cover off so that I can feel if the pump is running upon return. Or maybe I can figure out how to get the Zurich to monitor that M44 circuit turning on while I drive.