Are you sure a scan with a OBD-2 will find which one is not sending a signal? I just tried that with mt OBD-2 and it said 0 codes...............

 

I don't think you can. Nothing has ever come up on mine with an OBDII reader (mine is flashing). I was able to see which sensor was bad using a Snap On Solus (expensive). But that just tells you the serial number of the bad unit. There is a process where you deflate/inflate to determine which sensor is bad (still using the Solus tool).

I am fairly sure mine is the spare tire sensor. I am going to take it to a tire shop and have them verify which sensor and replace. I've just been too lazy to get it done.

 

when mine did this the Lexus dealership told me it was because I did not have a spare in the spare compartment.

 

I just picked up a set LTX M/S 2 for my GX at the local Costco - the rep told me they're cycling with Bridgestone and Michelin for the next 2 months with a rebate. I'd say it's worth it.

 

My light started blinking a few weeks ago. I tried the button under the steering wheel trick and that didn't fix it. I checked my pressure in all tires including the spare and one tire was at 28.5. Filled them all up to 35, but the light did not turn off immediately. After driving for a few days my wife let me know the light had gone off. After reading here I was sure it was a dead sensor since it was blinking and a solid light is what indicates low pressure. I was already planning on disconnecting the tire pressure monitoring system since I trust myself to check pressure. Oh well, problem solved...for now!

 

I know Techstream can read all 5 tire pressure sensors and temperatures. (I just did on my wife's 2006 GX470). I would think someone would be able to get that info into an app like Torque or a Scangauge. Should just be a simple query and response from the can bus, but the question is what address? Might need a can bus packet sniffer or something while using Techstream to isolate the correct address and response.