TPMS system fault

Britprius · July 17, 2017

I had the message "System fault" with flashing tyre, and red exclamation mark appear today. Checking with Techstream produced D3 tyre sensor faulty with it's code number. The other three tyre pressures, and temperatures were shown, but this does not tell you which wheel the problem is on.

With Techstream still connected I lowered the tyre pressures in each tyre noting which pressure altered (D1, D2, --, D4) marking the wheels accordingly. The tyre with the suspect transmitter was the rear NS.

I had the transmitter removed by my local friendly tyre dealer, and a rubber valve put in it's place.

I then went home with the offending item. Picture (1)

I gently prised off the cover of the unit. This took about 30 seconds. Picture (2)

Gently scraping off the soft sealant over the Battery. This took about 2 minutes. Picture (3)

I peeled off the tag connector. About 1 minute. Picture (4)

Gently prised out the Battery removing the underside tag. Again about 1 minute. Picture (5)

The Battery was a Panasonic BR2450 "Same as CR2450" reading 2.8 volts. Not having one of these to hand I replaced it temporarily with a CR2032 held in place with my fingers. I took it out to the car, and turned the car on. The system fault had disappeared, and was now showing a flat tyre obviously because I was holding the sensor without any air pressure.

I have ordered 5 tagged BR2450 batteries at a cost of £3-22 pence. As soon as they arrive one will be soldered back to the OEM tags, and the valve refitted. The other batteries will be kept ready for failures of the other valves.

The total cost per wheel with the charges from my tyre dealer for refitting, and balancing (£10) will be £10-65 pence. Plus 5 minutes work at my desk.

These pressure units could easily be made with a compartment so that the batteries could be change readily, but I suppose the manufacturers are making to much profit for this to happen.

John.

Farqui · July 17, 2017

Brilliant John / @Britprius, what a great 'mod'

Let us know how the final solution works.

It makes me wish I'd kept and dissected the one my tyre fitter broke earlier this year. The GS is the first car I've had with TPMS and I never gave it another thought.

I completely agree about the Battery compartment. I wonder if they're sealed to be more robust over a wider variety of conditions?

Britprius · July 17, 2017

9 minutes ago, Farqui said:

Brilliant John / @Britprius, what a great 'mod'

Let us know how the final solution works.

It makes me wish I'd kept and dissected the one my tyre fitter broke earlier this year. The GS is the first car I've had with TPMS and I never gave it another thought.

I completely agree about the battery compartment. I wonder if they're sealed to be more robust over a wider variety of conditions?

The sealant used seams to be the same as that used in bathroom ie silicon sealant. A Battery compartment made in plastic with a circular snap in lid and "O" ring would be more than adequate for sealing purposes. All that is required is to keep any water out put in by an air supply without a water trap.

John

KayCee · July 18, 2017

Well done john just shows what the dealers get out of us cash wise

Robert

Farqui · July 18, 2017

John, before reinstalling are you going to install a new seal on the sensor?

The low torque setting is a pain and over time has the seals leaking.

I see that you can buy TPMS seal kits, I wonder if the seal can be sourced separately from somewhere?

Britprius · July 18, 2017

1 hour ago, Farqui said:

John, before reinstalling are you going to install a new seal on the sensor?

The low torque setting is a pain and over time has the seals leaking.

I see that you can buy TPMS seal kits, I wonder if the seal can be sourced separately from somewhere?

I have a box full of various sizes of "O" rings. These are slightly softer than the OEM sealing rings, but seal better, and allow a small amount of movement of the valve. This helps prevent the valve being snapped off if it gets knocked.

These rings are a left over product from my working days as a electronics service engineer on industrial robots. The rings were used for sealing joints on both pneumatic, and hydraulic systems at pressures up to 10,000 psi on the robots.

The seal kits are available on eBay for about £6 each.

John

Britprius · July 18, 2017

After playing with Techstream on the TPMS I have found it is possible to look at the condition of the wheel sensor batteries.

On the data screen the only information concerning the batteries is the words upper or lower.

Going into the bar indicator graphs a green bar shows how much life is left in each Battery. The rear units on my car are full, and 90% "the full one being the temporary Battery I fitted. The two fronts are showing only about 5% life left. Good job I ordered five batteries.

The new Lion batteries I have tested read around 3.8 volts. The Battery I removed when the sensor stopped transmitting read 2.8 volts.

You can also see the actual tyre pressure in psi or bar, and the tyre temperature in C or F.

John

Farqui · July 18, 2017

Now that's mighty useful, well found.

The more I hear about Techstream the more useful it appears. I'd also like to a try a few custom settings and you can never have enough tech right?!

Britprius · July 18, 2017

2 minutes ago, Farqui said:

Now that's mighty useful, well found.

The more I hear about Techstream the more useful it appears. I'd also like to a try a few custom settings and you can never have enough tech right?!

The system is reasonably intuitive to use, and if you have a Toyota/Lexus vehicle more than pays for its self the first time you use it. Being able to save or print everything is also a nice feature.

John

Farqui · July 19, 2017

TPMS valve service kits are much cheaper stateside; https://www.carid.com/2007-lexus-gs-tpms-sensors/

Britprius · July 19, 2017

4 hours ago, Farqui said:

TPMS valve service kits are much cheaper stateside; https://www.carid.com/2007-lexus-gs-tpms-sensors/

Almost everything to do with cars is cheaper in the US. The problem is especially with smaller items is the very high postage costs.

If you know someone that visits the states on a regular basis "as I did when I was working" it was easy to bring things back.

John

Britprius · July 22, 2017

The batteries finally arrived from a seller in France today. Opened them up, and found they are not tagged.

I contacted the seller pointing out to him they were not what I ordered. He replied the pictures in his add do not show tagged batteries. I pointed out that at the top of the add, and lower down where the description says "Item specifics:- Tagged new batteries", and wished to return them as I could have bought non tagged batteries in this country cheaper, and with quicker delivery.

I now have to wait for eBay to intervene, and find a source of tagged batteries. Might have to build a welder and tag some myself.

Does anyone know if I am correct in asking the seller to send me prepaid return packaging for these. I do not see why I should pay for the return carriage costs. It is not the amount of cost involved, but the principle.

John

Bluesman · July 22, 2017

Not as advertised its down too them to provide return P&P. Just let eBay know and eBay will refund you and get the money back themselves. You'll be OK just need to be patient.

matt8 · July 22, 2017

What do you mean by 'tagged' batteries?

welshdragon · July 22, 2017

Hi John,

Assume you paid by Paypal; any hassle just raise a dispute with them too as you'll soon get your money back without returning any goods to the seller.

As Mike said it may take a little while but nothing for you to worry about-also suggest you leave appropriate feedback pointing out incorrect goods to warn any other potential buyers once you get sorted.

NemesisUK · July 22, 2017

1 hour ago, matt8 said:

What do you mean by 'tagged' batteries?

Britprius · July 23, 2017

18 hours ago, NemesisUK said:

Thanks you beat me to it

John

Britprius · July 23, 2017

Mike, and Tony. Thanks for the info on returns. I have never had to return anything on eBay before.

John.

Britprius · August 8, 2017

At long last I have received the correct batteries "tagged" from another supplier at £1-50 for five batteries. One of which has been fitted to the TPMS monitor, and fitted back into the tyre. No more warning lights, and Techstream shows the Battery on that wheel as full.

I am now waiting to see how long before the next sensor fails as two are showing low on Techstream. However at 30 pence for a Battery now held in readiness, and £5 for my local tyre fitter to remove, and refit I am happy.

John.

olumite · August 8, 2017

@Britprius are you at liberty to name the supplier of the tagged batteries?

Britprius · August 8, 2017

1 hour ago, olumite said:

@Britprius are you at liberty to name the supplier of the tagged batteries?

The batteries were from a company called "Phoenix power equipment LTD" in Yorks, but are available on eBay at similar prices less if you order from China. A single Battery is available "non tagged" at Maplins for £4. The Battery is a CR2450 button cell. Tags are not essential as just fitting the Battery in place and re-fixing the cover should work fine as the current required is minimal. However being a retired electronics engineer I like to dot the I's, and cross the t's.

Be sure when re-fitting the Battery the side marked + is upper most that is visible with the cover not fitted.

John.

NemesisUK · August 8, 2017

21 minutes ago, Britprius said:

However being a retired electronics engineer I like to dot the I's

Is that just a retired electronics engineer thing? Most would dot the i's

DaKa · September 21, 2017

Thanks John for the reference to this from the SC forum.

I wonder if anyone out there can confirm the batteries are the same CR2450 or something different?

Britprius · September 22, 2017

13 hours ago, DaKa said:

Thanks John for the reference to this from the SC forum.

I wonder if anyone out there can confirm the batteries are the same CR2450 or something different?

Yes CR2450 are the same batteries. It seems it is the 2450 that is the important part of the type number as many different letter prefixes are used. It is by no means essential to use tagged batteries soldering them in, but it does make for more reliable connections.

John.