2011 HHR LS - ABS & Traction lights on at the same time, but not all the time. NEVER did a check engine light come on. The message on Led says Service ESC and Service Traction. Initially thought it was wheel bearing.. There was a little play in bearing according to mechanic & I requested he change it. No difference in service lights.

There are a few things I have noticed since these lights illuminated, but do know whether or not they are in relation to it.

-- My tires are at 30 psi, but lately its been super hot and when I start driving psi is it at 26 or 27, taking almost an hour to get back to 30 psi, sometimes staying steady at 28 on two tires and 30 on the other two. If it goes to 29 the lights go off on dash.

I noticed that two of the lug nut covers recently came off the hub cap. There are no sensors in those covers, right?

Then lastly I noticed that there is something going on with the brake fluid/ster.cylinder, but the fluid does l not appear low ( I read that low fluid is s trigger for those lights to illluminate, but it's not low). It does appear over full and dirty.

If none of these are the reason, can someone please let me know what may be the problem. Thank you very much.

 

By way of education, not necessarily addressing the problem:
1. The tire pressure on the driver door placard is for cold tires. Cold means sat parked for at least 8 hours. The closer you start at that temp the less the pressure will build up with driving. Sounds counter-intuitive but physics is real, the heat build up comes from the sidewalls flexing.
2. the Tire pressure sensors are inside the tire attached to the valve stem.
3. Don't allow anyone to add brake fluid to the reservoir unless they are doing a brake job. The level tells you how much wear is on the front pads. It is a good idea to have the fluid replaced during a brake job.

Your problem is most likely a wire or bad connector for the ABS wheel sensors. A shop can scan the ABS system to find out which wheel to look at. You should replace the hubs in pairs; if one is worn out the other is not far behind.