Hi everyone,

So, Mercedes E350 2006 3.5 base, intergalactic mileage.
Error code P2734 - Pressure control Solenoid, STAR says its the K2 Solenoid and Mercedes want me to get a whole new valve body for about $3k, which with my salary, isn't going to happen anytime soon.

New battery, new alternator, battery and charging system is perfect. But still getting the pressure error code, which I guess is pointing to the K2 solenoid
(Also need new Inlet manifold as one of the rods has snapped at the engine connection...But that's another story)

So I'll be dropping the transmission, draining all the fluid, hopefully and then I'll need to take the valve body out and replace the K2 solenoid. I'm presuming I'll need to clean the valve body too. As far as I can tell,
it's a sandwich of two metal channels, can't really see how it'll fail, I suppose channels could get blocked?..

My question is this: there are black and blue tops, are all the black ones the same and the blue ones the same? I see on a parts store that the mercedes solenoids are sold in black and blue tops.
Does anyone have a diagram of where the solenoids are? That would be very helpful.

Also does anyone have the mercedes procedure on transmission (with torque converter) flush and refill method for the 722.9?

I'm trying to balance between fixing it myself or getting a service to repair the valve body, where they fix everything on the Valve body, TCM, solenoids, etc. what would you expect to be a fair price for something like this, been looking at GNN Motors in Socal. Has anyone used them?

Once that is done, I may just tackle the inlet manifold which looks like a pig of a job!

Thanks so much, this really is a great resource for keeping my car on the road.

Cheers,

Alex