Tire Pressure Sensor and svc tire monitor
 

Test drove a 2009 HHR LS at a lot. Yellow tire warning light was on and message in green read LOW TIRE PRESSURE. I liked the car and said fix it and I'll buy it. Tire pressure was fine, the sensor had been removed from one wheel (front left, I believe). They replaced the sensor and I bought it. Within 10 miles the tire warning light was back on this time with the message SVC TIRE MONITOR. Waddaya think? Something simple, or was the sensor removed to mask a bigger problem. Please weigh in if you have seen something like this before. Thanks.

Go Back and have them re program it again. Just takes a couple minutes. Manually check the air pressure in that tire to make sure it is inflated to the correct pressure first. Check the drivers door jam for the correct air pressure. Probably 30lbs. cold.
I have had the same issue several times at different dealers.

Welcome to the site, these TPMS sensors the batteries do die after 8 to 10 years, could be others are toast, you said fix it and you buy the car, now they need to step up, and fix it.

Thanks, silver and blue. It's going in on Monday.

There are directions for setting the TPMS positions in your Owner Manual (there's a link in my sig). Use the same directions when new sensors are installed.

Thanks, Don, for the link. I just downloaded the manual, as the car didn't come with one.

Aaaaaaak! Well, they reprogrammed it to do something. Warning light is off, tire pressure is displayed, but no odometer reading now. (I suspect they don't have the correct software installed.) Try again tomorrow. Oh...and they broke the electronic door lock while they were at it. Wish me luck.

Read the owners manual you downloaded. Sounds like you just need to scroll back to the odometer/temp read out.
(Use the INFO button to scroll. Button is on left side of steering wheel.)

Somebody had a computer and no training. Then decided to make a low tech problem a high tech screwup.

I take it that this is not a GM dealership? I fear that they will need to take it to a dealership now, I think they may have corrupted the firmware (only available for a price).

The TPMS is the same module as the remote door locks. Don't know how they screwed the odometer, the DMV might be involved now.

Oops. Bad writing on my part. Meant to say the DIC was frozen on tire pressure readout and can't scroll to other readings. Reset several times, now it seems to be fine.