TPSM system malfunction

[Walus]

Just got my new ES and the TPSM system malfunction popped out on the dash. Only two days after getting the car. 
Is this a common problem with these? Does it need a visit to the dealer to get sorted?

[beyond the blue]

Have you checked the pressures?

[peniole]

What does the dash say the pressures are? are they reported? if not check tyres directly. Haven't heard they're a problem on here yet. Hope not.

[Walus]

I reduced the pressure from what transpired to be 46 to 33 psi and the system is still indicating a malfunction. The pressure values are not displayed at all. All four wheel reading show - -.

[b4u2]

Hmm 😒 🤔 

[b4u2]

Strange isn't it, I would advise have a chat with your local lexus dealer 

[Walus]

It is very strange as even the reset of the system does not work. Pressing the OK in the ‘set tyre pressure’ doesn’t work. 

[Guest]

Did it malfunction after you reduced the pressures? If so it will have detected a pressure loss and need resetting. If not get back to the dealer

[Guest]

You answered my question as I posted it!!

[beyond the blue]

Sounds like you need to do a reset. It's not a quick process you need to reset and then take the car for a drive (up to an hour) l found before the new pressure will register and show on the screen, that's why your pressures are showing ----

[Walus]

I found this: https://seventrumpet.com/reset-lexus-es-350-300h-tire-pressure-system-tpms-light/

which is based on a manual and suggests that reset is confirmed by the TPMS indicator blinking 3 times. This does not happen in my case - indicator doesn’t blin 3 times. 
 

BTW, what is the correct psi pressure for the 235/45/18 tyres? 

[NemesisUK]

2 minutes ago, Walus said:

BTW, what is the correct psi pressure for the 235/45/18 tyres? 

It should be listed in the handbook and on the driver's B pillar

[peniole]

2.4 bar about 35psi

also about the -- the system takes a couple of minutes after startup before it reads out the pressure in bar

if you measured them cold at 46 psi then the dealer missed adjusting the pressure during pdi, 46 sounds like transport pressure to me. I once received a new Honda and they made that mistake.

[Guest]

Also you only get a read out if you are moving, well that’s what I seem to get

[Walus]

Will investigate and report back the fix (hopefully).

My bet is on a faulty tyre pressure sensor. 

[DTR]

Slightly off topic, but linked to tyre pressures.

When I first picked up my ES Sport, the ride was beautiful. Took me a while to suss the tyre pressure display, but when I did the readings were 2.1/2.2 bar when warm. I assumed they were correct. However after a cold night recently the warning came on. On checking pressures were down to 1.9 bar. The door jam and handbook recommended 2.3 bar  so I pumped them up to that (cold). As soon as the other half got in the car, she complained of a jiggly ride. I phoned Nottingham Lexus who suggested I bring the car in which I did straight away and their service coordinator took it away. He explained the necessity of resetting the warning point and showed me how to do it. We discussed the matter and he agreed that 2.2 bar ((cold) was a reasonable compromise. The ride is better , but still a little jiggly on poor surfaces. I am amazed how a small pressure difference makes a significant difference. Is this common with largish wheels and narrow profiles?

I am thinking of resetting to 2.1 (cold). Will it significantly affect tyre wear and fuel  consumption?

What are others doing please and any recommendations?

Thanks in advance.

[peniole]

3 hours ago, DTR said:

Slightly off topic, but linked to tyre pressures.

When I first picked up my ES Sport, the ride was beautiful. Took me a while to suss the tyre pressure display, but when I did the readings were 2.1/2.2 bar when warm. I assumed they were correct. However after a cold night recently the warning came on. On checking pressures were down to 1.9 bar. The door jam and handbook recommended 2.3 bar  so I pumped them up to that (cold). As soon as the other half got in the car, she complained of a jiggly ride. I phoned Nottingham Lexus who suggested I bring the car in which I did straight away and their service coordinator took it away. He explained the necessity of resetting the warning point and showed me how to do it. We discussed the matter and he agreed that 2.2 bar ((cold) was a reasonable compromise. The ride is better , but still a little jiggly on poor surfaces. I am amazed how a small pressure difference makes a significant difference. Is this common with largish wheels and narrow profiles?

I am thinking of resetting to 2.1 (cold). Will it significantly affect tyre wear and fuel  consumption?

What are others doing please and any recommendations?

Thanks in advance.

I assume since you said 2.3 that yours is an Fsport on 19"?

Had once a 19" low profile tyre on our Jag XF, yes small pressure changes made a big difference.

I'm on 18" and the recommended 2.4 is spot on for my taste.

You will see some increased side wear going from 2.3 (33psi) to 2.1 (30psi). Remember also the load capacity for each tyre is based on pressure. I would make sure that going down to 30 doesn't drop the load capacity below the weight of the car. Use this: https://tirepressure.org/general-metric-tire-load-inflation-chart?utm_source=LexusOwnersClubUK&utm_medium=ForumLinks

e.g. for mine a 3 psi drop will reduce load capacity by about 90lbs on each corner = 360lbs

[Julncamp54]

Tyre pressures have been a point of contention of mine for a while now, as what is the correct tyre pressure??

Lexus state  the correct tyres pressure is in the manual and on the door post label on the drivers side. Yes this is correct. So for my ES running  on 235/45R18 94Y  tyres. The pressure cold is 2.4 bar as stated ( below 160km/h). clear ?  Err no  question is what temperature does cold mean ??  If it’s 3 deg outside  15 or 20 deg outside.  From its design is a Japan cold  the same as UK cold ??
I take a mean temp so at say 15 deg C outside temp when tyres are cold I set externally to 2.4 bar then recalibrate the tpms system.

The TPMS system gives the tyre pressure once the tyre has actually warmed up during a reset condition. So one sets a cold pressure say 2.4 bar reset the tpms system  run the car  until the display reads a stable 2.4 on all the tyres., but the actual tyre pressure will be higher  but the system will, read 2.4 bar.as per its calibration algorithm. 

So if you externally measure cold tires at 3 deg c. It will be lower than 2.4 bar if the reset was done at 15 deg C . Conversely it will be higher if temp outside goes to 25 deg C.
I was told by the techs at Lexus the tpms  algorithm accounts for temperature change so as long as the tyres are measured cold at 2.4 bar this will give the best ride quality and best tyre wear.
 
so bottom line is ( as stated in the manual ) externally measure  tire pressure when cold then recalibrate tpms system.  The tpms will then monitor your tyres and advise if there is loss of pressure. Which is what it’s designed to do !
When I picked up my new ES the tyres were like 42 psi , so after 250 mile I dropped them down to be 2.4 bar then recalibrated as suggested by the dealer.

 

 

 

 

 

 

[NemesisUK]

1 hour ago, Julncamp54 said:

question is what temperature does cold mean ??

For tyre pressure it means the tyres are at ambient temperature. It means they haven't been run and heated up by friction and movement. For practical purposes this usually means checking them first thing in the morning. It's the ambient temperature that sets the base pressure for the tyre the manufacturer has determined will give the correct running pressure once the tyres are in use. 

[PRT68]

This ambient temperature should also be in the shade. In the morning, one side of my car is in the sun, and that side shows higher pressures. (My car shows individual pressures)

[NemesisUK]

Ditto. I rise early enough, (or wait for an overcast morning) to check the pressures before the sun rises above the trees and warms that side of the car. It's a significant temp/pressure difference once the shade goes.

[Julncamp54]

Quite correct early morning  cloudy day. To measure external tyre pressure. A 0.2 bar difference is ~3psi. 
and check certainly before any long journey using motorway for safety

[Walus]

A new angle on this. Does wheel rotation require reprogramming of the ECU so that it ‘learns’ new locations of the sensors? Is the system based on 4 transmitters (wheel sensors) and 4 receivers (in each wheel arch) that are paired up so that it can tell each individual wheel pressure? 
 

if that is the case a wheel swap would trigger malfunction and such an event would have to be programmed in.

[Malc]

reading the other day here on this Forum a member with an unfathomable TPMS " fault " ..  not his tyres or wheels ..... and his car having TPMS but too old for it to be an MOT failure ...  actually spent @£400 to simply replace all his TPMS " stuff " with Lexus ..  to remove the irritational showing of the fault

It might have been an SC owner 

Good luck with it all whatever .... I'm blessed with an old fashioned car where kicking the tyres occasionally was the fore to TPMS ....  and it works too 

Malc

[peniole]

2 hours ago, Walus said:

A new angle on this. Does wheel rotation require reprogramming of the ECU so that it ‘learns’ new locations of the sensors? Is the system based on 4 transmitters (wheel sensors) and 4 receivers (in each wheel arch) that are paired up so that it can tell each individual wheel pressure? 
 

if that is the case a wheel swap would trigger malfunction and such an event would have to be programmed in.

A wheel rotation is stated specifically in my manual for the ES. All you need to do is do the reset procedure for the TPMS system and drive. There are specific parameters, time, speed...etc. for it to learn the new locations and reset. Check your manual for specifics. On mine it's pages 461-462 and 478-482.