tire pressure light goes on and off, on and off

[janices_yaris]

I have a 2008 Yaris and recently the tire pressure light comes on while driving. It stays on for a several seconds or sometimes a couple of minutes, then turns off. Then later it will turn on again for a little bit, then turn off, and so on. It is pretty random. I checked the tires and they are 32psi each time. The light doesn't blink, it is solid.

Is there anything I can do before taking it into the dealer? I don't want them to charge me $100 for something minor that I can deal with myself. Thanks

[CTScott]

Check out this post for info on how to make the TPWS ECU tell you its issue by flashes of the TPWS light:

http://www.yarisworld.com/forums/showpost.php?p=197208&postcount=11

[janices_yaris]

Check out this post for info on how to make the TPWS ECU tell you its issue by flashes of the TPWS light:

http://www.yarisworld.com/forums/showpost.php?p=197208&postcount=11

Thank you but this seems a bit complicated. I don't even know what that connector is. I was hoping there is some button I can press :(

[CTScott]

Thank you but this seems a bit complicated. I don't even know what that connector is. I was hoping there is some button I can press :(

Unfortunately there's nothing quite that easy. The connector is the OBD (diagnostic) connector under the left end of the dash, right by the hood release lever.

[janices_yaris]

Ok thanks for your help. I have a related question. I will need to have the tires rotated soon. Would that cause the light to come on again, after I fix this current problem?

[CTScott]

Ok thanks for your help. I have a related question. I will need to have the tires rotated soon. Would that cause the light to come on again, after I fix this current problem?

Rotating the tires probably won't help or hurt (unless the issue is just a tire that is right on the edge of being under inflated). If you haven't done so, you should check the pressure on all four tires.

Also, as an FYI many cars monitor the spare tire (which most people forget to check on a regular basis). The Yaris though, does not have a sensor in the spare, so you are just concerned with the four main tires for this issue.

[2007tRD]

the light flashes because a tpms sensor[s] has a weak battery and needs to be replaced or re-learned to the tpms unit.

[bronsin]

How the tire pressure?

[janices_yaris]

The light now comes on and stays on for the entire time. The tires are 34 psi and stable.