Well, next one in this tragedy...
ETA=Electronic Throttle Actuator
V12 has 2 of theese, one for every intake/cylinder row, as far as I know the others have 1. The one on the drivers side acts as a "master" controlled with the throttle wire and then signal transferred to the passenger side (slave). So, more cables and crap on the drivers side then the passengers side one.
The passenger side is quite easily inspected on SL600 and if this one is bad, the other one is too. Remove LMM/MAF and for makin it easier aslo the air filter box (not needed, but easier). Remove the large rubber bend and then the ETA is fastened with 4 Allen bolts, nuber 5 I think. Also a few rubber hoses, there is a gasket between the ETA and the intake, might brake if not careful, but costs about $3 at MB.
Follow the harness from the ETA to the connector under a cover and remove the ETA from the car. First it should be cleaned with some kind of solvent/alcohol, should be nice and shiny on the inside.
There are 2 covers, one on each side, you only need to open the one with the harness, 5-6 torx screws, there is a gasket here aswell, don't know if you can buy this one, be careful not to break.
Under the cover you can see how bad it looks, probably like this:
As you can see in the background there are thinner pastelcolored wires, theese are for "internals" of the ETA and seem to be of better quality. Compressed air will clean out all the cracked insulation.
Try to identify all the wires, the have a letter printed on the circuitboard and the pins in the connector are numbered.
Be careful to identify theese two, this is the mains for the ETA-engine and it has a + and - lead, NOT MARKED, and I believe that you don't want the engine to be running the wrong direction:
The connector needs to be cut open, the first one i did with a knife and a small hammer, cut a lot, tap the knife with a hammer. This will cost you a lot of cuts on your hands aswell as twice the amount of beer and swearwords. The later ones I cut open with a Dremel.:
You only need to cut through the outer cover and then pry it open with a screwdriver. Identify wires as you touch them they will crumble:
Where the cable enters the housing is a little bit tricky, it is glued to the cable, in worst case, cut the wires and drill them out of the sealing rubber ring. New wires is starting to come in place, I didn't care much to follow the old color of the wiring, made a new diagram wich says what old color is the same as the new color:
New wires for the connector:
Heatglue from a gluegun works perfectly, justbuy glue that can take a little bit higher temperatures because of the engine heat.
Why heatglue? I wanted to try theese out before sealing them of for all future and heatglue is easily removed and seals properly. Besides, the connector is in a socket and cannot go anywhere, so for theese heatglue is perfect, if epoxyglued it will be tough to take apart again:
Just put it back in the car and get going with the drivers side, in principal the same thing, just a few more wires and also the throttle wire with control arm. The arm is easily pried out of its "ball", it is spring loaded so no worries. A little bit trickier but in general same procedure.