The HHR sat for maybe 2 days, temps dip into the teens or near subs at night but raise to between 30-50 during the day.
Last time I ran to the store at night and parked when I got back, everything fine. This afternoon 30 degrees I went to go to the store, started fine but the service airbags popped up again?
I backed up to turn around, was sick of seeing the airbag light so turned the car off, gave it a second then restarted.... WTH ? it started but was hesitating like heck then smoothed out and ran fine ( also airbag light was out and no service message ) drove fine to the store and back, started fine after as well.... Im almost to the point with this thing to trade it in. Its been a great car with no issues and great mpg, but Im just getting sick of all these minor scare tactics it keeps pulling out of the hat,,, no codes or anything, just does this stupid crap when it gets cold, never had a vehicle that pulled this crap, what gives???? And it has a full tank fresh fuel from last week.

 

How old is the battery?

 

The title says Trans acted weird.
You then write a whole story that doesn’t mention a transmission problem.
So exactly what are you asking ?

 

Opps , It did, After the hesitation and smoothed out when I went to go, the engine raced but the car barely moved. I thought it was my imagination but did it 3 times in total. I shifted to park then back to drive and it pulled fine after. I was tired and missed typing that in there...
Today was cold and ran just fine with no issue, it just does crazy stuff like this once in awhile, scares me with "uh oh repair bill" then laughs about it.... starting to hate it.

 

Long shot - in extreme cold weather, the transmission fluid will shrink and unmask a low level.

How old is the battery?

 

Not sure how old the battery is. Still cranking strong and not dead due to the cold which usually happens with a shorted cell.

 

Doesn’t take much to start these little Ecotecs. One shorted cell could give you a pretty strong nominally 10V battery. You could just put a Volt meter across the battery posts in the morning before starting. One shorted cell would prolly show about 10.2-10.7 V, might start the car just fine, yet the computer might complain. Been there.

 

Load test the battery and the other routine checks we all know of reading/posting here.
Spring is coming the warmer weather cures much and keep on going!?
You didn't mention age/mileage but sooner or later stuff happens to everything.
Good day/ week...

 

Could be solenoids, cracked fluid transfer pipes, loose ground wire, loose fuse box bolts, or TCM connection.

 

Yes, Ive dealt with a bad battery before in a Dakota, the dash would go nuts... Ill check it next time I head out