Indirect TPMS driving me nuts

Maintenance/Repairs
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Tire Pressure Monitoring Systems (TPMS) are the systems that do not have air pressure sensors inside the tires. Rather, they detect a low tire by comparing relative wheel speeds via the Anti-lock Brake System (ABS) wheel speed sensors. When a tire loses air, its diameter decreases slightly.

Older indirect TPMS are not as sensitive to changes in tire pressure as direct systems that ­actually monitor the air pressure inside the tire, but they are not as expensive ­either. An indirect TPMS is a relatively ­affordable add-on to a vehicle if it’s already equipped with ABS. Even so, the vast ­majority of vehicles that have TPMS use ­direct systems rather than indirect.

Federal law requires the TPMS to alert the driver if the pressure inside a tire has dropped more than 25% below the recommended inflation pressure. The same rules apply to direct and indirect TPMS. Many vehicles abandoned indirect systems for ­direct systems to meet the federal mandate.

One of the weaknesses of older indirect ­systems is that they may not turn on the warning light if all the tires are underinflated by a similar amount. If the recommended pressure is 32 psi, but all the tires are 24 psi (down 25%), the system won’t know there’s a problem because all the tires will be rotating at the same speed when the vehicle is being driven.

New systems are taking advantage of better wheel speed sensors and modules to make indirect systems work. Indirect TPMS began making a comeback in 2011 on all Audi models. The highly popular Honda Accord switched to indirect TPMS for the 2013 model year. The 2013 Mazda CX-5 is now also using an indirect TPMS. Some of the VW Golf platform vehicles have switched to an indirect TPMS. Most of these models have the ­optional ABS and stability control system.

But even the newer systems suffer from the ­inability to read the tire pressure when the ­vehicle is sitting still.

Indirect TPMS applications include:

Audi 2011-’14BMW X5 2002-‘05Honda Accord 2013-’14Lexus LS430 2004-‘06Lexus RX330 2004-‘06Mazda CX-5 2013-’14Mercedes C-Class 2007Mercedes SLK 2005-‘07MINI Cooper 2004-‘07Toyota Corolla 2005-‘07Toyota Matrix 2005-‘06Toyota Solara 2004-’06Toyota Highlander 2004-‘06Toyota RAV4 2004-‘05Volkswagen GTI 2007 and 2010Volkswagen Jetta 2005-‘07Where To Find Reset Procedures

All of these applications use a similar technology and strategy to detect a low tire, but there is no common reset procedure. Toyota is probably the best, with only one simple reset procedure for all of its indirect TPMS (though a slightly different procedure is used on the Lexus models).

With so many different reset procedures, it’s ­important to make sure you’re using the right ­procedure for the vehicle you’re servicing.

TPMS reset procedures may also be found in the vehicle owner’s manual (if it hasn’t been lost). Open the glove box and check the index in the owner’s manual for any TPMS information.

Indirect TPMS Reset Procedures

As a rule, most indirect TPMS have a RESET button for recalibrating the system. A reset is typically ­required after adding air to a low tire, after changing or servicing a tire, or after rotating the tires on a ­vehicle.

Audi Reset ProceduresFind the factory tire pressure specifications on the vehicle placard located on the doorsill on the driver’s side.Identify the tire that’s low on pressure and fill it up according to factory specifications.Put the key in the ignition and start the car, but don’t turn on the engine.Push the “Car” button located on the vehicle control panel.A menu will pop up on the screen, then scroll down and select “tire pressure monitoring.”Select “Store Curr. Tire Pressure.”The screen will then read, “tire pressures are being stored.”The tire pressure light should now be reset.Toyota Reset Procedures

On Toyota applications, the reset procedure is fairly straightforward, though it actually takes much longer to complete. Turn the key on (engine off), then press and hold the RESET button until the flashing TPMS warning light goes off. Or, if it’s not flashing, hold the RESET button until the light flashes three times. Then, turn the key off.

Hold on, though: The relearn procedure is not complete until the vehicle is driven at 19 mph or faster for at least an hour. You don’t have to do this, obviously, but your customer should be made aware of the fact that the TPMS reset procedure won’t be complete until the car has been driven awhile. During this time, the TPMS system may not be able to detect a low tire, so make sure all the tires have been inflated to the correct pressure ­before the ­vehicle leaves your shop.

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Tags:TPMS

This should take care of the original question.

Karl

102

I bet that’s because of pressure losses caused by driving, like the constant flexing of the tire on the beads. I don’t think the loss of air or nitrogen directly through the tire would be affected by driving. The CR test could well be the best way to test which gas diffuses less.

103

I think if he’s crucified, it’s because the density of asinine in his posts is about to form a black hole.

3 Likes
104

Remember the olden days in school, one teacher lesson was a man was executed while on death row." Governer do we execute him?"
Governer “No pardon granted”, he meant to say “No, pardon granted.”, 1 comma can make a big difference.

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105

“Dinner’s ready! Let’s eat grandma!”

or

“Dinner’s ready! Let’s eat, grandma!”

the common comma can save lives, folks. use them

2 Likes
106

Karl, Everything you say about direct and indirect TPMS is true but it does not explain why the indirect TPressureMS indicator comes on because of less than 3/32 inch tire tread wear between the front and rear tires on my 2015 Honda Civic. It makes no sense that a gov mandated tire Pressure monitoring system should be activated for any other reason than PRESSURE,

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Not that familiar with indirect systems and actually unaware of their existence until this thread. Sounds like some of the others are up to speed on indirect and their recommendations seem reasonable. Since both systems exist it may be a result of the wording of the statute that allows indirect. My opinion of Honda is comprised of great respect for their considerable engineering capability and gracious honor. Meaning I would expect them to build something that would satisfy the spirit and intent of the law and be useful to the operator. Try to get this thing reset if possible or inactivate it and use a tire gauge!

Karl

108

I will try one more time. The indirect TPMS works by measuring rotational speed at the tone ring. If the tire pressure is low, the tire shape will shrink slightly and rotate faster at the same speed.

Tire wear , even 3/32 will also cause the tire to be smaller and cause the tire to rotate faster. You apparently need to rotate your tires more often especially since you seem to be fixated on getting every last 32nd of wear to the legal limit and not much concerned with safety.

4 Likes
109

being completely ignorant of indirect TPMS as I am, I have to ask:

If an owner with a vehicle with an indirect TPMS system buys and installs 2 tires, with this give them a low air pressure warning- for having two new tires that are spinning at a (seemingly tiny,yet) different rate than the other 2? Is that what you all are saying?

I have heard of AWD vehicles needing to have tires that are somewhat close to each other tire wear wise, but never heard of this with TPMS.

110

Yes, until the TPMS reset procedure is completed.

1 Like
111

good question eddo. I think I will find out when i have to buy new tires this Spring

112

But will the reset/recalibration out lined in the Owners manual do it or does one have to go back to the dealer and be charged?

113

If the reset procedure in the manual doesn’t work, and you want the problem to go away, and your warranty has expired, you will need to take it to a shop and pay to have it looked at.

1 Like
114

Spring is not that far away and driving conditions this time of year are the worst. I think you need tires now.

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115

Yes and no.
They will (I do) get a TPMS light when I replace tires; whether it’s two or four, because of the alight changes in rolling circumference.

However, the system is not comparing their rotating speed to the other two tires, it’s rather comparing the rotating speeds of the new tires to those of the tires that were replaced. The new RF is compared to the old RF and the new LF is compared with the old LF. Either or both being different will trip the light.

That’s where the difference between “initializing” and “resetting” comes into play. When you “initialize” the system you set the reading for each wheel to its existing rolling circumference. That becomes the reference, or as I call it the “baseline” speed. You need to set the tire pressures where you want them before doing this. If you then get a low tire and refill it to the desired pressure, you can “reset” the warning light without resetting the “baseline”. However, if you get new tires you need to “reinitialize” the system to the new rotational speeds or you’ll get TPMS warnings.

“Direct” systems read the actual pressures from pressure sensors in the wheels. Rotating speeds are irrelevant.

2 Likes
116

With or without the comma the statement is wrong. 26psi was the recommended pressure for my 98 Pathfinder.

117

I remember our mechanic Showing me a busted up tone ring when replacing discs, maybe it is a problem with the tone ring.

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Volvo, How can you possibly make a long distance\unseen judgement on when i need new tires? the only facts you know about my tires is they they have ~19,000 miles and there is less than 3/32" wear between front tires and rear and that I only use them about 6,000 miles per year. On line Tire Rack lists reviews of people with the same OEM tires who claim 50,000 to an unbelievable 100,000 miles usage before replacement. Cars.com says “expect at least 50,000 miles from OEM tires”. Consumer Reports claims 60,000 to 70,000 miles from OEM tires.my tire have less than 1/2 of these purported mileages.

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mountainbike obviously understands how the indirect TPMS works but if your head is spinning like mine you will never buy another car with a indirect TPMS

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tread wear has no business being a factor in a T PRESSURE Monitoring System