TPMS light came on (as it also did recently - one was low. Aired up. Light went out) Thought oh maybe the one low recently might really have a leak. Stopped to check and all 4 are fine. Even a bit high than spec. (Spec is 30#; I tend to 32.)

Ah, must be the spare. When I got the chance I cranked it down and it was indeed low. Aired it but light is not going out. It flashes a long tone then goes to steady. Isn’t that a sensor issue?

Thinking maybe the spare might be at fault I tried taking it well away from the vehicle but no change.

Before I head off to Discount Tire I tried to see what I can find out myself. I have a cheap OBD dongle but none of the apps I tried read TP.

I also tried several TPMS-specific apps to no avail either. Some speak of holding the device near the tire; can an iPhone pick up the TPMS signal? That doesn’t seem right. Isn’t it just Bluetooth to the OBD dongle?

If I take a wheel away from the car will the system generate a warning because it’s not picking up one signal or if it doesn’t hear from a sensor it assumes all is well?

Any point to depressurizing and pumping back up as one site suggested? If I did it I’d put it on a jack to prevent tire damage.

 

Flashing light indicates not receiving a signal for at least 1 sensor. If you take a wheel away the light should flash. Keep messing with it and it will go in lockout mode. Make sure nobody tripped the main/ 2nd sensor button. If that’s ok or you don’t have one head down to discount so they can scan the sensors and tell you which ones are bad.

 

When my 2009 started with the light flashing i ended up Canfield them all figuring they are the same age. Discount tire was great and they will tell you which sensors have a low battery. I got my sensor from tpms.com. a quarter of the price from a dealer.