GS300 TPMS - Low pressure

[KevH]

Hi all,

I have a 2008 GS300 that recently has a small leak on the outside of the valve on the drivers front wheel. I bought a genuine TPMS fitting kit and asked a local garage to fit it. They couldn't get the old valve out if the car so had to cut it out (they showed me and it was jammed solid!). They copied the TPMS code and cloned it into an aftermarket TPMS but I was in a hurry and said I would re-initialize the sensors later.

The following day I pressed the TPMS button under the dash until I got the initialization message on the dashboard but the TPMS warning light stayed on and I still have the low pressure warning. I repeated several times and still the same.

Today I connected the car to techstream and it can read all 4 sensors and all are at the correct pressures I let some air out of the tyre with the new sensor and the computer displayed the new pressure correctly but the TPMS warning light is still on !!

Any ideas what Im doing wrong ? I tried initializing the TPMS with techstream connected and it doesn't write the new pressure values to the memory !

 

Thanks

Kev

 

[200h]

you normally have to register the new tpms valve id to the car

and not clone the old number to the new tpms valve

this can be done using carista

 

[Sami Tilander]

Hi Kev,

Did you drive a bit after pressing the initialization button? I've noticed that it takes time/miles after the initialization is completed...

Could can also see the ID of the sensor reporting low pressure (error code) using the TechStream: is it the new aftermarket sensor?

BR.Sami

 

[KevH]

Thanks 200h 🙂

I dont have access to carista but I do have techstream and according to the carista website it only supports basic diagnostics on a phase 3 GS 300.

Since the cloned valve has the same ID as the old valve what are you suggesting I program ? Should I try rewriting the existing codes?

According to techstream it can see and read all 4 sensors without any issues the issue is that the car doesnt overwrite the initial TPMS pressure and despite all 4 sensors showing pressures above the initial values it still thinks the pressure is low.

@Sami Tilander Yes I did drive it for a bit. Im just about to drive to a job so I will reset it again before I go. I can see the ID of all 4 sensors and all sensors read the pressure no problem and there are no error codes. All pressures are above the initial value. 

I will take a screenshot from techstream when I get home.

Thanks both 

Kev

[LenT]

10 hours ago, Sami Tilander said:

Did you drive a bit after pressing the initialization button? I've noticed that it takes time/miles after the initialization is completed...

According to my manual, if the light stays on after 20 minutes of driving then, unfortunately, they say a trip to Lexus Is indicated.  Although I imagine a good tyre dealer who’s familiar with TPMS could reset it.

In which case you probably already know if driving has done the job!

[KevH]

I drove for over an hour today and the warning light remained on 🥴

Ive attached a screenshot from techstream. The red box shows that all four IDs are programmed (the new one is ID3), the purple box shows that it successfully reads the pressure from all 4 sensors and the green box shows the initial thresholds all of which are below the measured value.

Two things that I noticed, the red arrow shows a "Threshold of low pressure" at 41.2 psi ! What is this for? I though it used the 4 individual values to trigger the warning light, also the Battery voltage for sensor 4 (old sensor) shows "Less" but its still reading OK.

Thanks

Kev

 

 

[Sami Tilander]

Hi Kev,

I've no idea what that separate low pressure threshold is... but have you tried to fill the tires to e.g. 42psi? Will the warning light disappear?

I will take a screenshot from my car for comparison...

BR.Sami

[Kijan]

Hello Kevin,

By looking at the report I can see that there is report of 'Less' on the ID4 Battery Voltage. Could it possibly throw an error due to Battery being old now?

All the best,
Bart

[KevH]

I  just blew all 40 tires up to 40psi on my uncalibrated and probably inaccurate compressor !! and the light has gone out 

I then plugged my laptop in to see what the sensors are saying but the screen on the laptop died just when I was about to open techstream ! Its not my week. Once Ive fixed the laptop I will take a look again 

Thanks

Kev

[LenT]

2 minutes ago, KevH said:

I  just blew all 40 tires up to 40 psi…

Just as well you weren’t using a foot pump. Kevin.  🙂

Still, sounds like you have a result.

[KevH]

Lol yeah just noticed I typed 40 tires 🤣 

[Sami Tilander]

I also failed to the connect to the TPMS ECU with my TechStream, so no screenshot yet... I need to investigate that more.

But good to hear that the warning light has gone! So, probably there is something wrong with the initialization procedure: it should set the thresholds lower than the current pressures on the tires...

BR.Sami

[Sami Tilander]

Ok, now I was able to get few screenshots from my car: first one is before pressing the init/reset button:

You can see that the "lower limit" is actually the lowest value of those thresholds... then pressing the init/reset button... and waiting a bit:

You can see that the tire thresholds have been changed, but the lower limit not yet... It probably will, but I've no idea how long that takes...

BR.Sami

[Sami Tilander]

Lower limit not changed after 24h and about 125 miles... still monitoring it...

[KayCee]

Well Sami you are on the right track Just depressure yr tyres to the correct pressure then  reinitlise it, at that pressure yu have set and all should be good it will set all to the 36 psi approx the pressure  you should be running at

[KevH]

Apologies for the late update, I had to transfer techstream onto another laptop and that wasnt as easy as it should have been lol.

So after blowing the tyres up the light went out and has stayed out, however there is a considerable difference in the pressures detected by the sensors and what my compressor says (no surprise).

However , it doesnt matter any more 😲 as I pick up a brand new ES F Sport next week 😊 . Ive owned the GS for 8 years so it was time for a change.

Thanks for all the help.

Kevin