@geg has successfully replaced the batteries. He posted a how-to: https://www.chevyhhr.net/forums/how-...battery-60730/


OOPs, not geg it was iroga65 in Belarus

We have tires here too, tyres is the usual way of spelling those rubber wonders in England.

and for geg’s method, you still have to break the beads.

I checked out greg's battery replacement but I don't think I'll go that way. Because I've got bad weather coming in and Harbor Freight's bead breaker was on close-out, I ran over and bought one tonight before the storm (they've still got a couple more in the box and one on display). I read through the reviews on HF about the breaker and saw two of them from HHR owners that used the tool to replace their sensors and recommended it.
I'll search around for a set of sensors and put them on order. Hopefully, I'll be able to swap them after the snow melts.
Thanks for all the hints and tips. This has been another learning experience.

iroga65 lives in a country where American things are rare and expensive. They are always looking for ways to repair things we tend to toss.

I got these from Amazon, 13598771 for $11.50 each in August. There now $13.00. Made in USA ACDelco. Just had then installed along with a new set of tires.

tvsteve,
Thanks for the tip but - Those
say they don't fit a 2009 HHR. My valve stems are metal with my fancy wheels. Amazon recommended these others
for the 2009 HHR. There are some lower cost ones listed but I don't see any ACDelco on that page. Evidently, I need pre-programmed 315Mhz sensors that the "re-learning" process will accept. I'd sure like to get a set that someone else and had good luck with.

Look for sensors like these

https://www.redi-sensor.com/application-look-up/

https://www.rockauto.com/en/parts/ac...)+sensor,12036

Or on EBay search 20925924 there are many to choose from.

interesting it would say they don't fit, I have an 09 and the 8771 is what mine called for per the VIN in the GM parts catalog ...but the metal valve stem thing is throwing me, mine are definitely rubber

Perhaps someone over the years replaced the OEM sensors with the metal type? Moonwink listed his ride as a 2009 2LT , so it should have 17 inch aluminium wheels, I’ve got a set on mine and they are the rubber style, he mentioned fancy aluminium rims, possibly SS 18” rims ??

When the guy at Firestone tried to sell me the "required" valve stem kit I asked him to show me. Turns out it is a chrome plated plastic cover for the stem and a cap with a new "special" core. $15/tire.
All of the sensors are the same, You need to get the correct stems that have a threaded bottom end for the screw.

Many alloy wheels have a hole that is only suitable for a different metal stem, most steel wheels can use either.

At NAPA the book used to claim that All HHRs require the metal stems with a included sensor.

Here is the Walmart pages with the different types.
https://www.walmart.com/c/kp/tpms-va...cement-sensors