I just bought a used 09 Caravan and noticed the tire pressure light on. I checked each tire and brought the pressure up from 28 to the recommended 36. I drove for a hundred miles and the light never went off automatically. ----- Questions:
1. Is there possibly a sensor in the spare wheel [donut size]? This was argued on another thread and never resolved.
2. If one sensor has gone bad, how do I know which one.
3. Is there a manual way to reset the sensors when the automatic way hasn't worked. [magnet next to the valve stem??]

 

If all tires are at the recommended PSI and the light does not go off, good possiblity you have a sensor issue. There is no sensor on the spare tire. If you have the high line cluster, it will tell each tire pressure and you could figure it out from there. If you have the lowline system with just the lamp and warning message, you will need a scan tool or hand held sensor sniffer. There is no manual reset to the system, just driving makes the sensors send their signal.

 

Thanks for that info. I only have the low line system so I assume I need to have it checked at the dealer.

 

if it is blinking, you lost a sensor, if it is solidly on, you are low on pressure
It's not gonna go of unless you fill your tire to 38+ PSI. so, fill it all up to 40psi, it should go off.

 

It blinks.... but only for a minute upon startup. Then it stays on solid.
What does that mean?
I'll go up to 40 and try.

 

if it blinks, that means one of ur sensor is dead. Does All of ur wheel have a sensor in it? are they Metal valve stem or rubber?
Dealer have the equipment to test the sensors, so does specialty shops like Just Tires.

 

Here's a description of how the system works

http://www.ricksfreeautorepairadvice...-tire-pressure

Also, you don't need to go to the dealer for diagnosis. Any qualified tire shop can pull the codes and replace a sensor. And they'll do it for a fraction of the dealer's price.

 

If you mean are the stems metal, as in solid to the rim and won't rock back and forth? No, they will move. I grab them by the cap and I can rock them back and forth.
You are probably going to say sensor type won't move around, right?

 

If you have a Sensor, it would look like


If not, that means the previous owner has removed it, probably because it broke, and he didn't want to pay for a new one.

 

Ah ha ! Just as I figured. A rigid metal stem. My stems don't look like that and as described earlier they are rubber and move around.
I have my answer. THANKS to all.