TPMS, but which tire?

I think I already know the answer to this, but if my TPMS light goes off is there anyway to tell which tire is triggering it?

I know these cars have no sensor and measure the rotational size of the tire. I had my sensor go off a few times with my winter tires and one tire was loosing pressure. Sure enough, tire was sealed on the wheel and had a slow leak. Once leak was fixed never saw sensor again.

Today, after having my summer tires back on the car for about 5 days, the TPMS light lit up. 3 of my tires were at 34psi, and 1 tire was at 33.5psi...so that shouldn't be enough to trip a rotational measurement change.

I almost suspect the tire shop didn't reset my sensor when they bolted on the new wheels and the light just triggered.

Is there any way of determining which wheel the car detected was measuring differently? I have a bluetooth OBD2 reader and Torque pro, but unsure if TMPS sets a code that it can read.

Figured it would be easier to ask then figure out on my own.

Unfortunately it doesn't tell you which tire. If all four tires are the same, reset the light and it shouldn't come back (as you said, your shop probably didn't do that).

sensor-less TPMS

That's strange, the Audis do tell you which wheel the problem is at. It seems like VW should be able to display the info. The car knows there's a problem. Therefore, it knows at which wheel

dieseldorf said:

That's strange, the Audis do tell you which wheel the problem is at. It seems like VW should be able to display the info. The car knows there's a problem. Therefore, it knows at which wheel

Click to expand...

That is very true - I'm guessing that it just notices a variance from the learned values and triggers a fault. I'm guessing Audi has actual wheel sensors installed?

I've noticed the same thing as the OP... switching between summers/winters that it takes a couple of days before triggering the light. The last swap I remembered to hit the reset button. Forgot this time. Gotta be close to 7 or 8 trips since swapping?

I'm sure you can find something in the VCDS measuring blocks.

I had a false warning once ( pressure was ok when I checked), but it told me which tire to check, right rear in this case, on the MFI in the warning window that provides vehicle status. In this case it was the second screen.

Don't know if this is helpful but the vast majority of punctures will be in the right rear.

Right, because that's where most of the debris is and rear, because you have to hit the object with the front to make it stand up.

Chris said:

Don't know if this is helpful but the vast majority of punctures will be in the right rear.

Right, because that's where most of the debris is and rear, because you valve to hit the object with the front to make it stand up.

Click to expand...

You know, I have had two punctures over the last ten years or so, and both have been right rears. Thanks for the info.

I find it annoying that the new Passat doesn't display each tire pressure.
My 2008 Touareg, 2011 Tiguan, and 2010 Jetta all displayed individual tire pressures.

lofranco said:

I find it annoying that the new Passat doesn't display each tire pressure.
My 2008 Touareg, 2011 Tiguan, and 2010 Jetta all displayed individual tire pressures.

Click to expand...

The Passat doesn't know what the tire pressures are, as it uses the wheel speed sensors for tire pressure monitoring. The other vehicles you mention have pressure sensors in each wheel, so they can actually display those pressures on the MFI.

VeeDubTDI said:

The Passat doesn't know what the tire pressures are, as it uses the wheel speed sensors for tire pressure monitoring. The other vehicles you mention have pressure sensors in each wheel, so they can actually display those pressures on the MFI.

Click to expand...

I prefer this system over the individual sensors... sure it'd be nice to know what individual pressures are, but I check mine regularly. I don't want to deal with the hassles (+$$$) involved in swapping around different tires if they all needed TMPS sensors.

A preference for individual sensors? Interesting! So puzzle me this...

It's of benefit to have battery powered sensors on all four wheels which are somewhat delicate at best?

It's of benefit to know that when one sensor fails it's off to the tire shop for a replacement and programming, along with a nice bill?

It's of benefit to buy four new sensors when purchasing an extra set of wheels when mounting snows?

And it somehow isn't easier to exit the car when a warning is displayed and do a visual check?

And the cost of a simple tire pressure gauge isn't a whole lot cheaper than individual sensors?

Mayhaps I don't understand. All the same I'm quite pleased not to be burdened with four little sensors that will go bad.

I think it is important to note that this "system" VW uses could also tell us the individual tire if they wanted to.

It uses the ABS tone ring to sense when one wheel is operating at a differential from the others, or from it's setpoint (reset button in glove box).

So the computer knows which wheel is suspect when it turns the light on.

Biggest problem I have had with it is false triggers from extended driving in the winter - one tire was in a dry groove and one tire was in a snowy groove.

50pascals said:

I think it is important to note that this "system" VW uses could also tell us the individual tire if they wanted to.

It uses the ABS tone ring to sense when one wheel is operating at a differential from the others, or from it's setpoint (reset button in glove box).

So the computer knows which wheel is suspect when it turns the light on.

Biggest problem I have had with it is false triggers from extended driving in the winter - one tire was in a dry groove and one tire was in a snowy groove.

Click to expand...

it does tell you which tire - see post #6 above.

vw_norm said:

it does tell you which tire - see post #6 above.

Click to expand...

Maybe on an SEL? I know my SE does not. Simple light on dash. Not even a beep when it came on.

vw_norm said:

it does tell you which tire - see post #6 above.

Click to expand...

I have a 2013 SEL Premium and it does not, unless there is somewhere I need to look for it?

50pascals said:

I have a 2013 SEL Premium and it does not, unless there is somewhere I need to look for it?

Click to expand...

Same here!

50pascals said:

I think it is important to note that this "system" VW uses could also tell us the individual tire if they wanted to.

It uses the ABS tone ring to sense when one wheel is operating at a differential from the others, or from it's setpoint (reset button in glove box).

So the computer knows which wheel is suspect when it turns the light on.

Biggest problem I have had with it is false triggers from extended driving in the winter - one tire was in a dry groove and one tire was in a snowy groove.

Click to expand...

The manual warns about certain driving conditions providing false responses.

gforce1108 said:

Maybe on an SEL? I know my SE does not. Simple light on dash. Not even a beep when it came on.

Click to expand...

No MFD in a SE? Supposed to beep/chime/make noise and set the light on.

Page 219 in the manual, shows up in the MFD:

I was changing over to the summer tires yesterday, so I deflated one winter to 25 psi and drove up to the shop (about 15km) and the TPMS didn't trigger. Changed to the summers and left one at 22 psi and the TPMS triggered on the way home. The warning light and a chime, but no message in the MFD.

Our car is a 12 Canadian Comfortline 2.5 gasser, roughly halfway between the American SE & SEL equipment.

Yours
Vern

vw_norm said:

No MFD in a SE? Supposed to beep/chime/make noise and set the light on.
Page 219 in the manual, shows up in the MFD:

Click to expand...

I have the MFD but there is nothing displayed about the TPMS. I even scrolled through to make sure I wasn't missing it somewhere, but nothing at all. Just the little icon of the tire. No beep either. My only guess is that the system detected that I changed over from snows to summer tires. (did the same going the other way). Both times it took a couple of days before the light came on. Maybe it knows something isn't quite right, but knows that it is not a low tire? A system malfunction vs an actual tire problem.

gforce1108 said:

I have the MFD but there is nothing displayed about the TPMS. I even scrolled through to make sure I wasn't missing it somewhere, but nothing at all. Just the little icon of the tire. No beep either. My only guess is that the system detected that I changed over from snows to summer tires. (did the same going the other way). Both times it took a couple of days before the light came on. Maybe it knows something isn't quite right, but knows that it is not a low tire? A system malfunction vs an actual tire problem.

Click to expand...

It's not displayed, but only popped up when it was triggered. It showed up as a status window, same place where it says service in xx days or xx miles as another screen - 2 of 2, etc....Since it happened once as a false alarm, it'll happen again, or maybe I can do a controlled test with an under inflated tire. I will take a picture and post.

gforce1108 said:

I'm guessing Audi has actual wheel sensors installed?

Click to expand...

No, Audi has been sensor-less since 2010MY in all cars (sent to the USA) except the A8 and R8. My sensor-less car does tell you where the problem is. I guess VW must elect not to display the location, but the system certainly knows there is a problem, and therefore, knows the location.

I'll try it again. Didn't check for a temporary message when the alarm first triggered.

Yours
Vern

Mine still has the icon lit. It came on a little over a week ago. I never actually noticed it turn on since it didn't beep at me. I just know somewhere along my trip I saw the icon lit (nothing written on the MFD). Once you mentioned that the MFD should display something, I scrolled through all of the 'windows', even stopping so I could access the setting one that you can't access while driving. Again - I've never actually had a low tire, just two instances where I swapped summer/winter wheels and didn't hit the reset button.

Mine lights the light, a chime goes off and it says, "please check tires" on the MFD.

I drove a 2014 CC on Saturday and it did tell the individual pressures as part of vehicle status on the MFD.

By the time I got out of the car I forgot to look and see if it had TPMS sensors in the wheels or if it just figured it out via ABS.

My guess is that it's doing it via ABS as all the tires said they were aired up to 40PSI, as this was a brand new car off the dealer lot - the dealership shouldn't be airing them up past 32-35.

If it displays the pressures in the MFA it must have wheel sensors.

-J