UDel

What does it mean when you get a yellow exclamation symbol on the dash and one of the tires is highlighted in yellow on the pressure readout screen. I noticed the yellow symbol on Halloween after I moved my car and when driving it tonight it stayed on and one of the tires on the display is highlighted but it shows the tire pressures and it is no lower then the others, 3 tires are reading 31 psi while 1 reads about 30. We have had a rapid cold snap so the cold air caused the pressure to go down pretty quickly but I never had that warning before. So there are batteries in the tire pressure monitors? Is this a sign the battery needs to be changed. How do you change them?

bclexus

The TPMS batteries cannot be replaced - new TPMS units would need to be installed. The batteries last a minimum of 7 years and most will last 10-12+ years, so it's doubtful the batteries are weak or (the TPMS units) need replacing.

It's my understanding that the yellow exclamation mark on the tire (on the instrument cluster) is supposed to indicate that a tire's air pressure has fallen below like 25%. Yet you are able to see the tire pressure values and all have plenty of air...so maybe it's just being quirky similar to my recent issue.

fuddyduddy

It's done it several cold mornings in a row.....

fortega

Mine was doing the same thing at the start of cold season. I suspected it was the temperature too but am past that now.

Most mornings it would not display pressures, then at lunch time I would get a reading and on the way home as well. That went on for about a month and then stopped displaying anything at all, just dashes. Now the orange low pressure light is on as well. Been driving around like that some a month. I've checked and rechecked pressure, tried resetting, and even bought an autel ts201(Suggested by MX73 on another thread) to see which sensor was bad.

Got the ts201 in today. Was excited to find out which sensor was bad and get it replaced so I could finally get rid of that light!!! And no luck 😭. All 4 sensors were read and batteries are okay. Now I'm wondering if the ECU somehow lost the ID codes of the sensors. But will need to buy something to check that.

fuddyduddy

Mine is still doing it intermittently..... and we have had cooler weather here (like around 45 degrees) in the mornings.

imjohnphan

To the OP, why not bring it into the dealership and let them diagnose it? This is what you typically suggest on many other forum posts. With Techstream and a Mongoose or miniVCI you can easily see the battery levels of your TPMS sensors. You probably have one that is low or multiple that are low battery and need replacement. Sometimes batteries last longer than others and also if you leave a tire low the sensor constantly sends out a signal and doesn't go to sleep so that accelerates the battery drain. I have had brand new sensors I purchased that the Techstream read as low battery too so I was a bit disappointed in that but it was already installed and mounted.

bclexus

I didn't need the dealership to diagnose the TPMS units, any more than I need the dealership to install and balance my tires or do an alignment. I actually dropped by my local Discount Tire store to have them check the condition of the TPMSs. The batteries all showed good and the tire pressure for all four tires was exactly where I had tweaked them.

The cooler/cold weather is what causes them not to display for some unknown reason...which I suspect is likely the batteries weakening a little from peak voltage even though all four batteries showed to be 'good'. When the ambient temperature is in the high-50s, that is where threshold seems to be. Any temperature higher than mid-50s and the pressures will display. When the temperature is a bit lower it takes some driving time to warm them up before they display.

bclexus

Another update to this old thread...

I suspect quite a few owners have replaced their TPMS units when they see dashes being displayed instead of the tire air pressure when they really didn't have to replace them. This is very common during colder weather months.

As the TPMS batteries age they have a tendency to only display dashes instead of the air pressure during colder temperatures. When this happens the air pressure usually displays again after driving a few miles, but sometimes it takes a number of miles before the air pressure displays. The colder it is the more likely it will take a long time to display the air pressure. This idiosyncrasy never happened when the car was much newer.

During this past February we had a [once in over a hundred years] week of near 0° temperatures in the Dallas area, and during that time I never saw the air pressure display even though the garage never got lower than 50° and one day during that period I drove the car about 40 miles and still no air pressure was displayed. However, I felt quite sure it would work properly again as soon as the weather warmed back up - because I have dealt with this before when it got cold weather. During warm temperatures the tire air pressure is always displayed either right away on startup or after driving just a few feet, just like when the car was new.

As an aside, I have noticed over the years that when the wheels/tires are rotated during colder temperatures it appears to trigger this strange behavior of displaying dashes for a period of time before the air pressure finally displays. Maybe the self-recalibration process (after wheel rotation) causes a period of time in which it drains the TPMS batteries (for which the batteries need to recover from being drained), whereas under normal operating conditions the TPMS sensors only send a signal once every so often.

► Maybe anyone searching Club Lexus wondering why their tire air pressure is displaying only dashes during cold weather months will see this thread. ◄