I have been fighting electrical and computer isssues with my 2005 C5. Initially I put a new battery in the vehicle thinking that was the issue. Then, I found I was getting water in the front passenger side floor board which had dripped on the the cars computer on the passenger side numerous times. Thanks to this board, I was able to determine that it was the air conditioning condensation hose that was blocked. I was able to crawl under the the vehicle and get this open and have about a 12 oz can of water drip on my arm. I was assuming that water dripping on the computer connections were causing the problems so I dried the side out and put the computer in to a plastic bag to protect against future leaks. The vehicle is now starting and running fine but after a mile or so the Reduced Engine Power, Service Engine Soon, low tire pressue, and other messages are occuring. Also, the air conditioner, windows, and radio do not function when this happens. All this while the vehicle continues to run fine. I have turned the vehicle off at least six times and the same senarios occur. Could the computer be damaged from the water? Is the computoer still wet and I cant see it? How could I fix this? How much would a new computer be? What else could be causing my issues? Thank you, everyone in advance for your previous help and any suggestions you have to correct my current issues.

 

You'll be getting codes; you need to see what they are to figure out exactly what the problem is.