Okay... this CLP/SSM is the black box with the vacuum pump and PC board in it... right? If so, I've replaced that with the other one I bought some time ago for the harness, and nothing works... no vacuum pump for the lock system... nothing. So I unsoldered the pump and tested with 12VDC and it works fine. I took my original pump off and tested it... IT works fine too. So, something that is supposed to energize that pump ISN'T. Now this leads me to believe that the vacuum RELEASES the locks and a spring/solenoid LOCKS things because it locks when the car is NOT running, nor is that little pump, and since I always used to start the car and hear that little pump running when I hit the key--even without engaging the start position--but just in the 'on' position of the key switch. Is there a vacuum chamber that holds vacuum as a reservoir? The wiring looks fine with NO signs of corrosion or green anywhere. Sigh. If replacing that CLP/SSM isn't the issue (and I realize it may still be, and that the 2nd one may also bad even though there is NO sign of any moisture issues with this one), then what? Go and buy a THIRD CLP/SSM only to find it is something else? I've reassembled both CLP/SSM units and will put the original back in and hook up the wires and vacuum... then I'll try testing with the car running and NOT running and see what I get. Love this car, but absolutely HATE Mercedes electrical engineering... way too far over the top of what's necessary.