Thread: Tire Monitoring System

this is my first time posting on these forums so hello everyone.

I recently purchased a 2007 Pontiac Grand Prix base model. It has 156,000kms, engine runs great and it's very clean inside and out. When I bought it, it had no warning/indicator lights on but of course a week later the tire pressure light came on. the yellow light flashes for about a minute then stays solid every time I start the car. also the DIC displays "Service Tire Monitor System". going through the DIC I can see that it only shows a pressure for one tire (Rear driver side) and nothing for the rest. all tires are at 30psi.



I did a bit of research on the issue and read that the actual sensors are part of the valve stem and the valve stems will be metal. but when I look at all my tires they are all rubber stems except the front driver side which is metal but not the one the DIC is showing a reading for.



Questions

-Does this mean I'm missing three of the four sensors?
-If that's the case why wasn't the warning light on before?
-Can I just get new sensors installed to get rid of the warning light?
-Will this have any effect on the ABS system or anything else?
-Is there any other way to get rid of the warning without buying new sensors?

-Does this mean I'm missing three of the four sensors?
Most likely, yes. It looks like 3 tires were probably replaced, which would be why the valve stems looks new compared to the other one.

-If that's the case why wasn't the warning light on before?
How long have you had the car? You said it was a recent purchase. The seller could have cleared the code prior to you buying it.

-Can I just get new sensors installed to get rid of the warning light?
Yes.

-Will this have any effect on the ABS system or anything else?
Traction Control and ABS may be impacted. Also, if your tires are low, it will affect speedometer readings.

-Is there any other way to get rid of the warning without buying new sensors?
You could have the code tuned out. I believe HPTuners can disable the low tire MIL.

Welcome RiGuy from a real R.I. guy. This is a real cool place to forum, take some time, bump around, chip in when you can, we all win.

BTW your car looks like a twin of my 06 base. Also looks like you could use some headlight restoration...pretty easy, they almost pop right out on these cars, don't forget the fog/running lights too....E

I used the Meguiars kit that comes with UV protectant that you apply after....afew months, so far so good....E

Many new sensors use rubber valve stems now because the metal ones break and corrosion in the winter kills them.

I'd ask a tire shop to scan each wheel and see what wheels still work but it's still possible they are regular valve stems with no sensors.

TPMS lights do not talk with the ABS or anything traction control related. Also HP Tuners does nothing with BCM/ABS functions, I just wanted to add those two so nobody looks for this thread in the future and thinks they are true.

You may have sensors in there they just need to be reset. It should say how to do that in your owner's manual. I would try that before ordering new ones.

The 1 new sensor/valve stem I have is rubber like the one you have pictured while the rest are still metal.

Originally Posted by TheRiGuy

I'm thinking that might be the case. Today I was cleaning the throttle body and disconnected the battery to avoid getting a code and when I re-connected it the tire pressure light was gone and the three sensors have a reading of 889 kPa on the DIC. obviously not correct but its not nothing. The reset/ learn instructions require holding down the lock and unlock buttons on the factory remote which is broken and requires re-soldering the battery holder to the board and I don't own a soldering iron. tried holding the buttons down on my command start remote but it doesn't work.

Some people have repaired their factory remote with foil tape. Search around on here for those how-to's and you may be able to find a fix that doesn't require soldering.