GM Volt Forum banner

1 - 20 of 30 Posts

·
Registered
Joined
·
534 Posts
Discussion Starter #1
I've had two Volts, a 2013 and a 2016. On both of them the digital tire pressure display was about 2 pounds low. I'm wondering if other people have the same experience. I also wonder if anyone has a display that is accurate. Two pounds makes a lot of difference.
 

·
Registered
Joined
·
4,608 Posts
I've had two Volts, a 2013 and a 2016. On both of them the digital tire pressure display was about 2 pounds low. I'm wondering if other people have the same experience. I also wonder if anyone has a display that is accurate. Two pounds makes a lot of difference.
Are you getting the tire pressure from the Driver's Information Console or from the MyChevrolet App? If you don't refresh the app then the information being displayed is as of the last time the Volt was plugged in. On my 2017 Volt the tire pressure sensors are overly sensitive but generally agree with my tire pressure gauge. Park in the sun and the tires facing the sunny side will read higher pressure. Drive a mile or two and the front tires will read higher than the rear tires. Charge the Volt and the tire closest to charging port and the onboard charger will be warmer and read higher pressure.

I keep my Volt's tires inflated to 2-3 pounds above the recommended 36 psi. If my tire pressure gauge and the Volt's tire pressure sensors are all reading a few pounds high my tires are still properly inflated.
 

·
Registered
Joined
·
2,359 Posts
Using a good quality pressure gauge I've found that all of my tires give a solid, reproducible, read of tire pressure.

It's just that three of them give the CORRECT pressure and one is always 2 psi low.

So as long as three of them say 40psi and one says 38psi, all is good in OHM-RIDE land :)
 

·
Registered
Joined
·
772 Posts
I don't use the tpms to set operating pressure. I use my own pressure gauge for that. I just use the tpms to warn me of slow leaks. The low pressure warning pops up at what, 34 lbs.? That's good enough for me.
 

·
Registered
Joined
·
1,429 Posts
Using a good quality pressure gauge I've found that all of my tires give a solid, reproducible, read of tire pressure.

It's just that three of them give the CORRECT pressure and one is always 2 psi low.

So as long as three of them say 40psi and one says 38psi, all is good in OHM-RIDE land :)
The sensors have a battery built in which wears out eventually. You have a 2013 so it's possible that the sensor that reads low needs replacing. TP sensors are usually good for longer than 4 years but it's not unlikely that a sensor's battery could wear out in that period. The next time you rotate or swap your tires you might what to have the sensor replaced.
 

·
Registered
Joined
·
3,439 Posts
TPMS systems are thrown off by elevation changes. This is because they do not measure the tire pressure relative to ambient pressure like a handheld pressure gauge would. They measure absolute pressure and subtract a preset value for ambient pressure. This is a "known issue" for all TPMS systems and I don't think there is any fix for it. At very high elevations, it can actually cause low pressure alerts even when the tires are properly inflated.

Your profile puts you in Salt Lake City, which is over 4,000 in elevation. I think this is your issue. Just make a mental adjustment for the reading.
 

·
Registered
Joined
·
4,608 Posts
Sounds like a good reason to take a drive to the beach, stay overnight. In the morning, when you know your tires are cold, you can set your tire pressure at sea level using a tire pressure gauge. Note the tire pressure read out on the Driver's Information Console. Drive home and the next morning when the tires are cold note any difference in tire pressure displayed.
 

·
Registered
Joined
·
3,439 Posts
TPMS systems also measure temperature and make an adjustment to reported pressure based on that. This can muddy the waters even further when trying to correlate to a handheld pressure gauge. This is done so you don't see a sky-high reading after driving for a while (and be tempted to vent air).

Just use the TPMS for its intended purpose: to alert you in real-time to a significant loss of pressure below a critical value.

For precision pressure readings and fine adjustments to pressure, use a handheld gauge.
 

·
Registered
Joined
·
700 Posts
My dash reports the tire pressures on all four wheels consistently at 5 PSI under the actual reading from a pressure gauge (gauge=40, DIC=35). I'm sure elevation has some impact on this as I am in Colorado, but that seems like a lot to me. This is a pain when the actual pressure is the recommended 38 PSI and the DIC reports 33 PSI when a low pressure warning is triggered. It is not much of an issue as I try to run at 40-42 PSI, but it would be nice if there was some type of calibration offset available to make this read right.
 

·
Registered
Joined
·
3,439 Posts
The pressure drop from sea level to 4,000 feet (Salt Lake City) is 2.0 psi. To 5,000 feet (Ft. Collins), it is 2.47 psi. So half of your variance is elevation. The other half might be some combination of inaccuracy of your TPMS sensors, your handheld gauge or temperature compensation (or that you live West of town).
 

·
Registered
Joined
·
3,945 Posts
Using a good quality pressure gauge I've found that all of my tires give a solid, reproducible, read of tire pressure.

It's just that three of them give the CORRECT pressure and one is always 2 psi low.

So as long as three of them say 40psi and one says 38psi, all is good in OHM-RIDE land :)
Seconded. Their calibration may be questionable, but they're very consistent. Which is the important bit. Get 'em right once externally, then just watch for changes.
 

·
Registered
Joined
·
13,556 Posts
Using a good quality pressure gauge I've found that all of my tires give a solid, reproducible, read of tire pressure.

It's just that three of them give the CORRECT pressure and one is always 2 psi low.

So as long as three of them say 40psi and one says 38psi, all is good in OHM-RIDE land :)
All of my TPMS sensors match my tire gauge and the DIC. I have 2 sets, snow tires and all season tires. I suspect the OPs tire gauge might be the one that is off given my sample set.
 

·
Registered
Joined
·
534 Posts
Discussion Starter #16
Elevation makes a lot of sense. I never thought of that. It's sort of obvious, too. Thanks.

That's why everybody isn't screaming about it. Just the ones at high altitudes.
 

·
Administrator
Joined
·
19,969 Posts
TPMS systems are thrown off by elevation changes. This is because they do not measure the tire pressure relative to ambient pressure like a handheld pressure gauge would. They measure absolute pressure and subtract a preset value for ambient pressure. This is a "known issue" for all TPMS systems and I don't think there is any fix for it. At very high elevations, it can actually cause low pressure alerts even when the tires are properly inflated.

Your profile puts you in Salt Lake City, which is over 4,000 in elevation. I think this is your issue. Just make a mental adjustment for the reading.
That was my thought as well.

BTW, my tire sensor batteries are over 6 years old, still doing fine.
 

·
Registered
Joined
·
3,533 Posts
how about checking with a handheld pressure device AND a hand held tpms unit
and the hand held tpms will trigger the sending of current data.

-------------
"That's why everybody isn't screaming about it. Just the ones at high altitudes."

I thought that screaming and coffee both did not work well at high altitudes but I guess the coffee is because of the HARD bean water :)
 

·
Registered
Joined
·
1,785 Posts
A safety device with electronic components should simply shut off when the battery is low or signal the console computer that it is not working. Giving the wrong value is hazardous.
 
1 - 20 of 30 Posts
Top