Gunther - I have the same problem...I am glad to know that the pump is working and it is just the control valve. I think I have located the "control valve" under the hood. I believe it is on the drivers side (like you said) right on top and is about 2 inches in diameter. Is that right? Now - on Gmpartsdirect they list a
By-pass valve, Check valve, and a Control solenoid. Which one is it? I'm sure it is the most expensive one (haha) but, I thought I would ask. Thanks!