Low Tire Pressure Warning System

See Pages 150-152 of your 2007 Owner's Manual. Sensors are located inside your wheels at the base of the valve stem.

 

<div class='quotetop'>QUOTE(Rest @ Mar 6 2007, 05:40 PM) [snapback]401227[/snapback]</div>

The warning lights when pressure drops 25% of the set value in any one tire. At 42/40 you will have to lose more than 25% before the light comes on. Ensure all the tires are at the desired pressure then reset the sensors as per the owners manual.

 

<div class='quotetop'>QUOTE(Rest @ Mar 6 2007, 02:40 PM) [snapback]401227[/snapback]</div>

You have identified why you got the second warning. EVERY TIME you change the pressure, rotate the tires, get a flat, boost the pressure, drop the pressure, get new tires, etc., etc., take 15 seconds to reset the system. The TPMS doesn't know what your tire air pressure is, only if it decreases from when it was reset. No reset, it can get confused.

Regarding battery life, ask this question again in a few years. Those are long-life batteries. You'll run the tread off your Integrity tires long before the battery wears down.

 

<div class='quotetop'>QUOTE(Rest @ Mar 6 2007, 09:27 PM) [snapback]401457[/snapback]</div>

Actually, you can't. If a sensor battery fails, the warning light will be on all of the time. Check your tires. If they are all okay, the only way to know which wheel has a failed sensor battery is to take the car to a dealer who has a scan tool who can get a reading from individual wheels. Even then he will need to maipulate the pressures to figure out which wheel is which.

Except if you encounter a faulty battery in a sensor, this is a long way off. I think they are supposed to last ten years.

 

So, when you replace your tires, you can prophylactically replace the battery. What's the problem?

 

<div class='quotetop'>QUOTE(Bill Merchant @ Mar 7 2007, 03:26 AM) [snapback]401525[/snapback]</div>

Problem is............. you cannot replace just the battery in a tire pressure sensor. You have to replace the sensor.... About $150 each if memory serves me correctly.

 

the basic rundown on TPMS

 

<div class='quotetop'>QUOTE(Bear68 @ Mar 10 2007, 11:55 AM) [snapback]403453[/snapback]</div>

I think it is $104 each. Less, but still a lot.

galaxee

Thanks again for your summary of the system!

Is the $104 cost correct?
Is the advice regarding determination of which wheel might have a failed battery correct?
Is there a preventative (prophylatic) procedure other than simply replacing the sensor units when changing tires?

As these things age, they may be troublesome unless we simply learn to ignore the warning light and check the tires the old fashoned way.

 

when DocVijay got some new sensors for his new rims that's what he paid, but that was like a year ago if not more and costs do go up.

for the rest, i'll have to answer tonight when DH gets home. for sure the system is far from perfect.

 

<div class='quotetop'>QUOTE(Bear68 @ Mar 10 2007, 11:55 AM) [snapback]403453[/snapback]</div>

I stand corrected, sorry. What were they thinking in not making the battery replaceable?

 

<div class='quotetop'>QUOTE(Bill Merchant @ Mar 10 2007, 05:39 PM) [snapback]403503[/snapback]</div>

Weird thing is that the service manual tells you to rip the battery out of it for recycling before throwing the sensor away! Looks like it might be soldered in. I'd like to look at one and see if it could be replaced by someone not afraid of a soldering iron.

[attachmentid=6842]

- Tom

 

<div class='quotetop'>QUOTE(Bill Merchant @ Mar 10 2007, 02:39 PM) [snapback]403503[/snapback]</div>

If you think about it , Bill, those things get thrown about rather violently. That battery needs to be held tight to keep from flying off. It is not just the spinning but the bumps too. That doesn't even consider the occasional tire machine.

 

<div class='quotetop'>QUOTE(Bill Merchant @ Mar 7 2007, 12:33 AM) [snapback]401463[/snapback]</div>

Bill, how do you reset the system?. Which buttons do you hold and where are they?

Mary

 

<div class='quotetop'>QUOTE(Masnyd @ Mar 10 2007, 05:55 PM) [snapback]403569[/snapback]</div>

Hi Mary

Bill must be away from his computer.

The button is under the steering wheel at the bottom of the dash to the right of the button for the Smart Key. You must first set the tire pressures to the level that you prefer. Then hold down the button for the TPMS until the warning light on the dash flashes three times (it should be about 15 seconds). That is all. It is reset to the new pressures. If a tire defates to 75% of the set pressure, the warning light will come on.

 

<div class='quotetop'>QUOTE(Masnyd @ Mar 10 2007, 05:55 PM) [snapback]403569[/snapback]</div>

Allannde was right, I was eating dinner...

As a hint from another post, if you think 25% is too much of a drop, you can overinflate your tires by 10%, reset the TPMS, then reduce the tire pressure to the level you want to drive at. Now you'll get a warning when a tire is down 15%. Other ratios also work.

 

<div class='quotetop'>QUOTE(Allannde @ Mar 10 2007, 06:51 PM) [snapback]403489[/snapback]</div>

exactly right.

no, when the sensor fails it fails. nothing you can do to stop it from happening.