SwedeSpeed - Volvo Performance Forum banner

1 - 20 of 31 Posts

·
Registered
Joined
·
344 Posts
Discussion Starter · #1 ·
My warning came on yesterday regarding low tire pressure in one of the tires. What I thought was the right front tire indicated low pressure. This morning I checked the pressure on all four tires. I found one tire with low pressure (about four pounds), but it was the left front tire. I guess the warning showing which tire is low is indicating a perspective of looking up from the ground at the car and not looking down on the car as I assumed.
 

·
Registered
2018 Volvo V90CC T6
Joined
·
1,039 Posts
My warning came on yesterday regarding low tire pressure in one of the tires. What I thought was the right front tire indicated low pressure. This morning I checked the pressure on all four tires. I found one tire with low pressure (about four pounds), but it was the left front tire. I guess the warning showing which tire is low is indicating a perspective of looking up from the ground at the car and not looking down on the car as I assumed.
It's super weird if that's true. Anyone would assume it to be a top view rather than a bottom view. The only time I have had a low tire-pressure warning is when it suddenly cooled down and the warning popped up on all 4 wheels, so the perspective didn't matter.
 

·
Registered
Joined
·
1,528 Posts
Odd.

The last time I had a punctured tire in my SPA xc90, the indicator on the screen corresponded to looking down onto the car; what appears to be rear left tire (i.e. one on the bottom left of the screen when looking at the screen) agrees with the rear left tire having a puncture. The other tires were ok (including rear right, if the diagram were from below the vehicle looking up).
 

·
Registered
Joined
·
2,016 Posts
Odd.

The last time I had a punctured tire in my SPA xc90, the indicator on the screen corresponded to looking down onto the car; what appears to be rear left tire (i.e. one on the bottom left of the screen when looking at the screen) agrees with the rear left tire having a puncture. The other tires were ok (including rear right, if the diagram were from below the vehicle looking up).
Same here, it's a top down look in my experience as well. I had the right rear punctured with a thumbtack and it had a slow leak that triggered the iTPMS at 4psi diff.
 

·
Registered
Joined
·
174 Posts
I had my front right tire ruptured totally and the iTMPS does not warn anything whatsoever. Even when my wife was driving the flat tire, there was no warning at all and she felt the difference and got the spare changed. What a total failure on the system for that. Ironically, when the spare tire was put on, the system started warning about inflation. What a joke. When the tire was totally out, there was NO warning.

Also, this system was complaining previously about requiring low pressure whereas all tires were all properly inflated. We had to do an onscreen re-calibrate. Anyways, a very bad implementation of the TMPS as far as what we feel.
 

·
Registered
Joined
·
344 Posts
Discussion Starter · #7 ·
The warning screen shows what appears to be a picture of the undercarriage of the car, which leads me to believe it is trying to show the vehicle from the bottom up (and yes I have an early 2018). But the other three tires had consistent pressure. The left front had the lower PSI. And the warning only showed the underinflated tire while the car was moving. Once stopped the warning only indicated one of the tires was underinflated just as it did with my 2016 XC60.
 

·
Registered
Joined
·
277 Posts
That's interesting, I've always found it to correspond with a top down view. But I recently got a weird message while driving - it showed a low tire warning on dash but all 4 tires showed as low (all orange). Did a quick visual and all looked fine so I reset it a couple of times. After the 2nd reset, it came on again for the driver side rear. I checked pressure and it was down 2 psi, no nails. Topped it off and all is fine, just strange that I got a warning for all 4 tires first and only 1 tire was slightly low. Overall I find the system to work fine, I was notified of low pressure due to a nail pretty quickly once.
 

·
Registered
2018 Volvo V90CC T6
Joined
·
1,039 Posts
All 4s lighting up is normally a result of the tire temperature cooling down by a lot. Happened with me driving from the (warmer and faster) roads of Nevada to the snow frozen mountain (colder and much slower) roads of Utah/Colorado!
 

·
Registered
Joined
·
1,504 Posts
I had my front right tire ruptured totally and the iTMPS does not warn anything whatsoever. Even when my wife was driving the flat tire, there was no warning at all and she felt the difference and got the spare changed. What a total failure on the system for that. Ironically, when the spare tire was put on, the system started warning about inflation. What a joke. When the tire was totally out, there was NO warning.

Also, this system was complaining previously about requiring low pressure whereas all tires were all properly inflated. We had to do an onscreen re-calibrate. Anyways, a very bad implementation of the TMPS as far as what we feel.
Yes, it's a joke, but a bad one. If dTPMS would have been an option, I would have paid for it.
 

·
Registered
Joined
·
277 Posts
Which would make sense but this happened on a very warm day about an our into a drive. I've had the sensors on previous cars trigger for rapid drops in temp but that wasn't the case here.

All 4s lighting up is normally a result of the tire temperature cooling down by a lot. Happened with me driving from the (warmer and faster) roads of Nevada to the snow frozen mountain (colder and much slower) roads of Utah/Colorado!
 

·
Registered
Joined
·
277 Posts
Keep in mind that all systems take a certain amount of time to register a drop in pressure so they're not really good at blowouts even if the system uses sensors. I used to have a BMW and one day I had a sidewall failure on the highway at 70mph; everything was fine, then I felt a weird shake, then I felt a big pop and car started pulling all within a few seconds. I managed to pull it over and saw that the entire inner sidewall was gone and I could put my hand on the inside of the wheel. No warning from TPMS until I was almost pulled over.

TPMS were mandated in US after the Ford Explorer rollovers from tire failures due to under inflated tires. Not sure if they were really designed to deal with rapid loss of pressure in emergency situations.

I had my front right tire ruptured totally and the iTMPS does not warn anything whatsoever. Even when my wife was driving the flat tire, there was no warning at all and she felt the difference and got the spare changed. What a total failure on the system for that. Ironically, when the spare tire was put on, the system started warning about inflation. What a joke. When the tire was totally out, there was NO warning.

Also, this system was complaining previously about requiring low pressure whereas all tires were all properly inflated. We had to do an onscreen re-calibrate. Anyways, a very bad implementation of the TMPS as far as what we feel.
 

·
Registered
Joined
·
1,504 Posts
All 4s lighting up is normally a result of the tire temperature cooling down by a lot. Happened with me driving from the (warmer and faster) roads of Nevada to the snow frozen mountain (colder and much slower) roads of Utah/Colorado!
Do you mean this happens with iTPMS, or with dTPMS?
 

·
Registered
2018 Volvo V90CC T6
Joined
·
1,039 Posts
Do you mean this happens with iTPMS, or with dTPMS?
Mine is an MY18. SO I'm guessing I do not have the actual TPMS sensors on the wheels. I don't know if that's called an iTPMS or dTPMS.
 

·
Registered
Joined
·
190 Posts
Same here, it's a top down look in my experience as well. I had the right rear punctured with a thumbtack and it had a slow leak that triggered the iTPMS at 4psi diff.
Same here. It is top down. TPMS flagged top right wheel (on display) with issue. Sure enough passenger front wheel had a screw in it. Seem to me those with bottom up have TPMS programmed incorrectly.
 

·
Registered
Joined
·
1,504 Posts
Mine is an MY18. SO I'm guessing I do not have the actual TPMS sensors on the wheels. I don't know if that's called an iTPMS or dTPMS.
MY2018 has iTPMS. The "i" stands for "indirect", meaning htere are no sensors.
It works by comparing rotation of the wheels via the ABS sensors.
Since the temperature of all the tires will drop the same amount when driving
in the cold, I don't see how this can result in all 4 of them lighting up as you described.
I would rather think the system wasn't functioning as it should when it occured.
 

·
Registered
2018 Volvo V90CC T6
Joined
·
1,039 Posts
Since the temperature of all the tires will drop the same amount when driving
in the cold, I don't see how this can result in all 4 of them lighting up as you described.
In fact, I think the system performed accurately by lighting up all four wheels as the Tire pressure in all four dropped the same amount. The iTPMS must have detected the pressure dropping below its threshold and notified me. The pressure low lights went away by themselves once I made it to the lower altitude with much less snow and much higher driving speeds. I'm guessing the pressure must have been back above the threshold so the lights went away.

I find the above behavior perfectly accurate. I do not think the iTPMS sensors compare their pressure values to other tires. They must be comparing it to a set value once we fill up the tires and lock-in the calibrated values. That's my guess.
 

·
Registered
Joined
·
62 Posts
Throwing this out there for any feedback.. New 19 xc90, currently 8k on odometer. I've had TPMS low tire warning come on 6-8 times in the last 3 months with warning on all 4 tires each time. I checked tires & balanced air at ~38psi the first few times and no low pressure. Once I could attribute to cooler morning weather. Several times the light has came on before I've even fully backed out of the garage - so no time for rotation reading I assume. Now when it comes on I just reset.. I'll mention it on first service but since I can recreate the problem I dont expect it to get resolved.
 

·
Registered
Joined
·
2,319 Posts
Throwing this out there for any feedback.. New 19 xc90, currently 8k on odometer. I've had TPMS low tire warning come on 6-8 times in the last 3 months with warning on all 4 tires each time. I checked tires & balanced air at ~38psi the first few times and no low pressure. Once I could attribute to cooler morning weather. Several times the light has came on before I've even fully backed out of the garage - so no time for rotation reading I assume. Now when it comes on I just reset.. I'll mention it on first service but since I can recreate the problem I dont expect it to get resolved.
Did you perform a recalibration? It is possible your car is not properly calibrated.
 
1 - 20 of 31 Posts
Top