Have been dealing with non start issue all of a sudden on my 06 LS.Had to have it towed to the local stealership .They reflashed the BCM and made me a spare key to the tune of $153 .I went by alone and paid the bill,went out cranked up and moved car to a storage parking area.My wife rode back with me after hours to pick it up.Got in and it wouldn't crank again!!I called the ASM next morning & told the story.He apologized later saying that they had programmed new key incorrectly and it was ready again with no further charges.Picked it back up drove(tried both keys first) home.Next morning only like 56 degrees outside.No start again!! We have been having extremely warm temps here in VA for October like low 80's during the day.It seems I can go out to start car in the evenings after work and it starts right up! Next morning same deal (NO Start!!) This is driving me nuts and makes no sense.What does a 20 degree temp change have to do with the passlock system?? I must say I feel fortunate because it has 96 000 on the clock and this is my first real issue.Sorry for being so long but does anyone else have an idea????

 

Battery?

 

By "won't start" what do you mean?

Turns over but won't fire?
Doesn't even turn over?
Turns over very slowly?

Although I'm sure they probably tested the battery/charging system, but there is a lot of reason for a "no start" situation.

 

 

Sorry I failed to mention we tested all the normal things first.Battery is fine.I have a gut feeling it could be the ignition switch but that requires another reflash if changed.When you turn the key everything lights up as normal .I think I even hear the fuel pump at first!No starter response and yes we made it turn by jumping power to it too! I do not understand why temperature has anything to do with it???

 

Bad starter selonid? The temp could be causing condensation. I have noticed a lot of condensation in the mornings around here and I am up in Lynchburg, about an hour away.

 

I hadn't considered that as a factor but having read all the postings on this site it will make you consider a lot of things.Well it's back at the dealer again as of this morning so I'll let everyone know what they tell me this time!

 

I have the same problem, but the opposite. My car starts when it wants. I have one remote start fob and sometimes it just turns on runs for 15mins and cuts off. The week I bought it the alram went off 3am and the car was running. I keep the keys in the kitchen drawer. It's done that a few times the two years I owned it. Freak thing.