TPMS light.

[rallytaff]

Checked all 4 tyres. 39 front, 36 rear. Light on dash didn't go out after trip. Any ideas?

 

[Capri to ST]

Maybe one of the sensors is bad?

 

[rallytaff]

Unfortunately, our cars don't tell you which one. I'll go to the dealer tomorrow and get one of the mechanics to look at it. If the tyres are still keeping the correct pressure, I can ignore it for now.

 

[SteveS]

If you have one of the cheap TPMS sensor training devices (roughly $10 on Amazon) you can use it to determine which wheel has a bad sensor. Then you can buy a replacement sensor (set of 4 for $25 or genuine Motorcraft 1 for $36) and just have a tire shop swap it. They should charge you the same as a flat repair. All they have to do is break the bead, unscrew the sensor from the back of the valve stem and screw the new one on, then reinflate the tire.

 

[Intuit]

The sensors have batteries so have a finite life span. Might make sense to just go ahead and do all of them.
Had a TPMS diagnostic tool that displayed temperature and battery level, in addition to temperature.

Do NOT purchase anything manufactured by Autel. They sold a butt ton of defective devices and won't support them.

 

[rallytaff]

Due to the heavy rain we had, I wasn't able to do that. It had crossed my mind, so I'll do that this morning as the rain has finally passed.

 

[madhatter]

don't order them from amazon either. i've gone through 2 complete sets before i changed the vendor and now they're fine. Something about the ones amazon are selling, even the genuine motorcraft ones, are bad. maybe they sit on the shelf for so long the batteries go bad, or something else, not sure. 2 sets is not a coincidence IMO. 8 tire sensors, all had to be swapped out within 6 months.

 

[Intuit]

They go dormant after awhile. I rotate between sets seasonally. It can be sdubidly hard to get them to activate; especially if the tool is bad or needs a battery. If you have one that won't activate, drive on it for a few days then try again. Still won't activate, try a different tool. Try repositioning the tool to the tire sidewall if the valve stem position doesn't work. Second tool I bought that is going bad, won't work unless I break it out of its case which directly exposes the coil. Some sensors will be more sensitive than others so there may just be that one, that doesn't "like" the bad tool.