Tpms sensor indicator On the dash is flashing when ignition is on, and remains a steady light when turn on the engine.

tire pressures are 32-33 on all corners but i did not checK spare

pressing and holdIng tpms reset button did not do anything. Was pressing it for like 20 seconds and was expecting it to flash bit it didnt.

any clues?

 

Possibly one or more tpms sensors need battery replacement. You could also try to use Techstream to see which tpms(s) cause the tpms light to be lit. Another cause could be the tpms sensor itself goes bad and does not transmit its data ...

 

thanks....I do not have Techstream and not sure where to get it....thought about replacing just batteries but called two Lexus dealers and both parts depts are telling me that batteries are built-in, ie you have to replace the whole sensor. Four TPMS sensors on ebay are about $64 and thats not too bad.

 

If you're handy, you could replace the builtin batteries yourself ... search youtube for Lexus tpms battery replacement

 

I saw a YouTube video saying the spare also has a tire pressure sensor? Might be worth checking? Also read somewhere the batteries should be good for 10 years give or take. You’re definitely coming close to that. Interested to hear the outcome and resolution here. Good luck!

 

I just bought a 2010 RX 350 and it has a tire pressure warning light when I start the car up it flashes for a while and then the light is solid on with no more flashing. It does not have the full-size spare so it does not have a sensor on the spare. Do you think it is the batteries in the sensor which I will buy new sensors and have them programmed, The tires that are in the car are 245/60R18 the label on the door says the original tires that came with the car are p235/60r18 do you think that would make a difference with the sensors? Love my Lexus it is the first one I bought. Thank you for your help

 

Likely just the batteries in the sensor. You are at about the early stage of failure.

 

+1, flashing for 10 seconds then solid means ECU has a problem connecting to one or more tire pressure sensors. Recommendation is to use Denso replacements, $35 each at Rockauto BTW, but tire removal required...

 

Thank you I was not sure if the batteries, or maybe the different size tires, My next tire rotation that is coming up I will replace the sensors, Can you replace just the batteries, or do I have to replace the sensors?

 

I wish you could replace just the sensor battery but unless the technology has improved recently, you must replace the entire sensor assembly (which includes a new battery).

 

Here is some extra information:

Each sensor needs to be registered (programmed) with the vehicles computer.
Battery in the sensor is supposed to last 8-10yrs.
Battery in the sensor is "not" supposed to be replaceable, bit it can be replaced. If you replace the battery, then the registration/programming is not needed.

My lesson learnt ... If for any reason you have to unmet a tire [new tire/fix-a-flat etc] and the sensor's age is 5 yrs or more, go ahead and replace the sensor


Salim