I have a 2008 C5 with H3+, and I changed the rear height sensor as the car wouldnt raise or lower. After changing and clearing codes, I tried to raise the car and nothing happened. After some searching, I tried to push the purple signal wire on the pump tighter, and the pump sprung back to life. But, if I let go, the pump stops. I can also press the black box and the pump goes on, so is the problem in the signal wire connector, or is it in the pump itself, eg a bad connection in the pump or in the black small box on the side?
Cheers, T.
You'll need to check the electrical connection at the plug and if it's not there then it may be internal.