Tpms all 4
 

My 2009 HHR 2.4L has been sitting in the drive way for 2-3 months and no one drives it. I'm gonna clean it up and sell it. I went to start it and to no surprise the battery was dead. I put it on slow charge overnight and this morning I started it using the fob. Unlocked the doors using the fob. Then I noticed the SVC TPMS monitor. All FOUR tpms are showing the three dashes. Do I just need to relearn the TPMS sensors or is there something more to this?

Give it a try.
Did you drive the car for 2 minutes over 25 MPH?
Could be the batteries died.
2008 models had a software problem.

The key fob is an aftermarket and will not put the car into relearn mode, so I would have to flash the key fob off my Maroon (Wisconsin Red) HHR to the 2009 white HHR just to put it into tpms relearn mode. I dont have insurance on it so I did not get it on the main street, but drove it around the neighborhood. I just find it hard to believe that all four batteries died at the same time. I might get it on the street and put some speed and time on it and see if it clears up. Thanks.

The TPMs go to sleep when the wheels are not turning. It take atleast 25 MPH for at least 2 minutes to wake them up.

They don't like sitting too long with all the electrics doing their thing.