I know there are many posts about no start- no crank on C6's- just thought I would pass along some info from personal experience. I had the "push starter button- gauges sweep- no crank, mine was intermittent but seemed to be getting worse. I'm not much on newer electronic problems, I do know it wasn't setting codes- had it checked more than once. So i decided this was something that I would have a dealer handle, thinking it was one of my modules that was going bad .I need to mention after reading a lot of posts on here it isn't one of these common problems- bad battery, bad key FOB battery, loose connection at starter solenoid, or any of the rest of the suggestions i've seen on here. So i take it to dealer #1, they had it for a week- no solution- said it was too intermittent for them to find problem. so i took it to dealer #2, same scenario except they said I needed new battery because their tester showed a possible cell problem, so i reluctantly agreed on a new battery- but after a week they came up with nothing- they didn't know what to do either. So I take it home and i'm thinking this is going to have to be me that will eventually find the problem. So I put my 'common-sense' hat on and thought i'd try the clutch switch first, the car is 16 yrs old and the switch is your basic push button make or break contact switch that is used everytime the car is started. I disconnect the plug and take a cutoff paper clip and cross the connector- car starts every time for 2 weeks and I installed new switch I got off Amazon (around $10.00) - car is fixed- starts perfectly! So i fixed my car in 10 minutes using common sense- 2 dealers couldn't fix it- they were relying on all their electronic diagnostic equipment- which doesn't work all the time!

 

I've had several issues like this, the only positive experience I've had from somebody else doing the work on my car has been new tires. My hud broke and in the process of fixing it they screwed up the mixer on my climate control (one side blows hot and the other blows cold) when I took it back they left the car setting till the engine got cold and said they couldn't find the problem. I drove it till it warmed up and took it back, same thing, I explained the mistake they made in their diagnostics, they wouldn't listen.

Speed shop couldn't find my bad cam and actually caused damage to the car and of course denied it, my faith in humanity is utterly destroyed after 10 years of little to no help and having to rely on figuring it out and fixing it myself.