I've owned many Lexus prior to my 2017 GS350 and this is a new one. Around 54k miles on the clock.

Over past week or so, whenever I first start car in the morning all pressures show --- (dashes). Driving car for as long as 30-40 minutes and the dashes remain so the system does not "wake Up". I know once in a while on other cars system would wake up after 15-20 seconds.

Pls note there are no warning lights (Red tire light) of any kind at any point. After that initial drive, I turn car off and restart it, the pressures now appear as usual?
Subsequent restarts during the day and the pressures DO appear fine for the rest of the day.

There's been no tire replacements recently nor any rotations. I even reset the system thru the dash but it doesn't seem to have any effect.

Dealer is going to hook up car tomorrow to check the data logs from the tire sensors to check the sensor battery health. If that turns up nothing, going to have to leave car overnight for them to witness it happen themselves.
Don't see how the batteries in the sensors would be involved. If they were malfunctioning/low, would think it would light the tire light and stay in error state?

Anyone ever come across this before?
NOTE: I've never had a TPMS issue in any LEXUS i've ever owned.

Thanks !!

 

@NJLEXES - I'd say you have one (it only takes one) TPMS battery struggling to transmit a strong enough signal. This in turn causes the CAN (Controller Area Network) communication system to decline or reject the other three signals, thus throwing dashes. What happens when you shut Off the car and then restart it, that results in resetting the CAN and that one struggling TPMS battery gains enough strength to barely clear the threshold to send a strong enough signal to satisfy the CAN, so it works normally for a while. Chances are, it's going to be an on again/off again event until that one TPMS is replaced or all four preferably are replaced.

With a 2017 model year vehicle that was almost certainly made 9 years ago in 2016 (and is going on 10 years ago) - it's about time for the TPMS batteries to expire.

 

thanks BC!! Was hoping you would see the post.
Strange thing though never got a RED tire light.
Thought that usually appears with sensor battery issue. Also if temperature change related the sensors stay dashes even after 40 minutes of driving too.

Guess one of the batteries is “marginal”maybe.
Car was built in Feb 2017 and purchased in July 2017.

Will let you know what the dealer finds. Hope my Platinum VSA saves me again :-) if needed

 

Dealer checked it out.
No log abnormalities (resets) or sensor issues!!!

Guess I’m a lucky guy.

Next step is leave car at dealer overnight so they can observe first start of the day and see the malfunction “live” as it happens.

Maybe a glitchy module?
Looks like we have one for the record books........

 

9-10 years old sensor batteries. As bc said. The batteries are failing. Time for new sensors.

The big box Tire stores all have the wireless checker for this. They stand outside and read each one to tell.

 

Thanks....

If one (or more) of the sensors are on their way out, Hoping the sleepover at the dealership will reveal the culprit sensor(s) when they start the car first time in the morning.

 

If you find one culprit, you wouldn't replace just that one TPMS, would you? All the others are the same age!

 

I have the Platinum VSA warranty which expires in June 2028 on the GS. According to the dealer, the sensors WOULD be covered by the VSA. Because of that, they would only replace the failing sensor under warranty.
As such, I wouldn’t want to pay out of pocket for the other sensors at this point.

I’d still have time in case the others fail before 6/2028

Hope this helps explain my thought process
better. Appreciate your feedback and info as always !! 👍

 

They may be covered, but I'd double check.

It might categorize TPMS sensors as a wear-and-tear item that is not covered.

 

On my 2013 the older the sensors got the longer they would take to respond in colder weather.

 

I've had this issue on my car, but I was told the previous owner put in aftermarket sensors. The light turns on and off when pressure gets low, but it doesn't display the readout on the dash.

 

You might be onto something…..
interestingly enough, I went away with car this weekend to Upstate NY
it was a bit of a hot spell lol
temp was around high 50’s in the morning.

for the first time in like a week, the sensors worked as they should for 2 days straight!!

previously to that for several days here in NJ, they showed the dashes for like 4-5 straight days on first startup. It was a bit colder than that.

 

@NJLEXES - Search for 'Cold TPMS Dashes' in the 4GS forum and you'll find many, many threads and posts about how cooler/cold ambient temperatures affects the TPMS, making them throw dashes.

Usually the problem is one TPMS that has a weak-ish battery causing it to dip below the threshold of being able to send a strong enough signal required for the CAN communication system.

 

From my experience even though it showed dashes the tpms light still worked immediately at start up when I had a low tire.

 

After 3 days straight of warmer temps at startup (SAT-SUN-MON) and working fine, THIS morning ambient Temp was back to around 45 degrees & guess what?
Back to dashes.
As you state BC, Definitely one or more of the batteries in the TPMS sensors is marginal... just don't know which one(s) are the culprit at this point.

Put off my appt at the dealer this week as morning temps are a bit inconsistent (High & low) this week.
Next week we're due for a cold snap so that's when I'll leave it with them overnight to make sure they can duplicate the problem and find the problem sensor(s)

Thanks again for all the input !