TPMS

Ben1001 · March 8, 2018

Does anyone know how the TPMS works on the IS Gen 3 please?

looking at a set of winter wheels however I can’t find out whether the IS tyres have a TPMS sensor in the valve which I would need to buy for the winter set?

ColinBarber · March 8, 2018

Yes they have sensor valves. You would need four of them.

mhult · March 8, 2018

According to the owner's manual, there are pressure sensors in the valves. The manual states that one should let a Lexus workshop or other workshop with similar qualifications and equipment register the ID codes for the sensors with the car. Maybe there is a way to disable the TPMS in order to reduce the cost of the winter wheels, if one is willing to live without the safety the system brings (and circumvent the regulations that require TPMS on all new cars).

Britprius · March 8, 2018

1 minute ago, mhult said:

According to the owner's manual, there are pressure sensors in the valves. The manual states that one should let a Lexus workshop or other workshop with similar qualifications and equipment register the ID codes for the sensors with the car. Maybe there is a way to disable the TPMS in order to reduce the cost of the winter wheels, if one is willing to live without the safety the system brings (and circumvent the regulations that require TPMS on all new cars).

This would bring an MOT failure, and possibly void the insurance in case of an accident. TPMS in my opinion is a waist of resources, but is now part of modern vehicle safety systems, and as such we must live with it. Blame the EU.

John.

rayaans · March 10, 2018

On 08/03/2018 at 8:32 PM, Britprius said:

This would bring an MOT failure, and possibly void the insurance in case of an accident. TPMS in my opinion is a waist of resources, but is now part of modern vehicle safety systems, and as such we must live with it. Blame the EU.

John.

Yes but knowing that the MOT is a test at one specific point in time, surely you could just switch the wheels over for the MOT and run winter tyres the rest of the time.

Britprius · March 10, 2018

20 minutes ago, rayaans said:

Yes but knowing that the MOT is a test at one specific point in time, surely you could just switch the wheels over for the MOT and run winter tyres the rest of the time.

But could you guarantee you only had an accident with the correct wheels on. Your insurance states you must keep your car in a roadworthy condition, and they would then, argue that it was not as it would not pass the MOT.

It is also unlikely that any reputable tyre fitter would fit tyres without the monitors as they could also become liable.

John.

rayaans · March 10, 2018

3 minutes ago, Britprius said:

But could you guarantee you only had an accident with the correct wheels on. Your insurance states you must keep your car in a roadworthy condition, and they would then, argue that it was not as it would not pass the MOT.

John.

An MOT is not proof of roadworthiness though.

Roadworthiness can mean different things to different people and is a rubbish term to use.

As far as insurance is concerned, if the accident was caused by a sudden drop in tyre pressure thats probably the only time they could actually say that it was because no TPMS was fitted

Britprius · March 10, 2018

21 minutes ago, rayaans said:

An MOT is not proof of roadworthiness though.

Roadworthiness can mean different things to different people and is a rubbish term to use.

As far as insurance is concerned, if the accident was caused by a sudden drop in tyre pressure thats probably the only time they could actually say that it was because no TPMS was fitted

In principle I agree with you, but I doubt your insurance or a court if you took it that far would agree with you. You could also argue a holed rusty sub frame or chassis had nothing to do with an accident, but if it was obvious the car was not road worthy would they still pay out.

The MOT is a certificate of road worthiness. If you change something after the test that negates that it does not matter what it is in law the car is not road worthy. My, and your opinion on what is road worthy does not count.

In theory it would also class as a modification.

John

J Henderson · March 10, 2018

@Ben1001 I've got 4 of these genuine Toyota TPMS valves that are surplus to requirements.

They came off the 3IS F-Sport wheels that I use during Winter, so they should be suitable for your car.

One of them was damaged during removal, but the guys repaired it with silicon sealant. I have no idea if it still works or not, but the other 3 valves ought to be OK since they've not been on a car since 2015 and are still within the expected Battery lifespan.

I wouldn't want much for them. Let me know if you're interested.

rayaans · March 10, 2018

2 hours ago, Britprius said:

In principle I agree with you, but I doubt your insurance or a court if you took it that far would agree with you. You could also argue a holed rusty sub frame or chassis had nothing to do with an accident, but if it was obvious the car was not road worthy would they still pay out.

The MOT is a certificate of road worthiness. If you change something after the test that negates that it does not matter what it is in law the car is not road worthy. My, and your opinion on what is road worthy does not count.

In theory it would also class as a modification.

John

The MOT is not a certificate of roadworthiness though. It just means it was deemed to be roadworthy at time of testing. Your car can be not roadworthy despite having an MOT - for example if it has bald tyres or a windscreen chip in the field of view 1s after the MOT. Its just a snapshot of the cars life

reeac · March 10, 2018

My IS300h Sport has TPMS according to the handbook but I can't find any button on the lower dash to use to normalise the system. Any clues, please?

Britprius · March 10, 2018

Lexus hide the button up among the pedal mechanism not on the plastic dash covers.

John

reeac · March 10, 2018

Thanks, I'll have a look there. Imaginative thinking to put them down there. I have to say that the diagrams in the handbook aren't very clear or is that just me?

Pompeyscouser · March 10, 2018

Pompeyscouser · March 10, 2018

I hope the above picture helps

Carl1983 · March 11, 2018

18 hours ago, rayaans said:

The MOT is not a certificate of roadworthiness though. It just means it was deemed to be roadworthy at time of testing. Your car can be not roadworthy despite having an MOT - for example if it has bald tyres or a windscreen chip in the field of view 1s after the MOT. Its just a snapshot of the cars life

I have to agree with ryaans here. unless the accident was caused by a sudden drop in pressure the insurance company wouldn't be too bothered. my friend had a very serious accident was air lifted to hospital etc. he had after market wheels on his car with completely different tyres sizes to what the manufacturer stated. Aviva paid out no problem infact as it was quite a rare care (corolla compressor) he got slightly more than he paid