Tire Pressure "On-Board Sensor" accuracy vs.
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Originally Posted By: Snoman002
Is there a calibration routine? My g8 has you drop the pressure to zero on each tire one by one in order to learn the tires 'position'. Perhaps this also serves to recalibrate the sensor.
Sounds good. Basically, if you could get the sensor to atmospheric pressure, this is defined as zero gauge pressure, so one could hit a reset there. I need to research that. Seems like a thing to do at tire change.
Edit: I did find a tire-position identification procedure, like after a tire rotation: http://www.silveradosierra.com/how-to-ar...ires-t4022.html
but it seems there is no calibration to zero gauge pressure.
Is there a calibration routine? My g8 has you drop the pressure to zero on each tire one by one in order to learn the tires 'position'. Perhaps this also serves to recalibrate the sensor.
Sounds good. Basically, if you could get the sensor to atmospheric pressure, this is defined as zero gauge pressure, so one could hit a reset there. I need to research that. Seems like a thing to do at tire change.
Edit: I did find a tire-position identification procedure, like after a tire rotation: http://www.silveradosierra.com/how-to-ar...ires-t4022.html
but it seems there is no calibration to zero gauge pressure.
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Originally Posted By: bdcardinal
The system in my Mustang and my mom's Fusion is absolutely terrible. All it does is turn a light on, it will not tell the tire that is low or any PSI reading.
The G37 is the same. That's good and bad. I don't have to fiddle with them relearning their position after a rotation. But, the darned things are so picky that, with a specified cold pressure of 33 pounds, they go off at like 30 pounds. So, essentially, if I set the cold pressure to be 33 pounds at 50 F in the garage in the winter, and then go outside and it's -40, I'm going to have trouble.
The system in my Mustang and my mom's Fusion is absolutely terrible. All it does is turn a light on, it will not tell the tire that is low or any PSI reading.
The G37 is the same. That's good and bad. I don't have to fiddle with them relearning their position after a rotation. But, the darned things are so picky that, with a specified cold pressure of 33 pounds, they go off at like 30 pounds. So, essentially, if I set the cold pressure to be 33 pounds at 50 F in the garage in the winter, and then go outside and it's -40, I'm going to have trouble.
I don't think so. At least there's no indication how to do so in the FSM, even if you have the fancy Nissan/Infiniti Consult machine. I just have resigned myself to keeping a good eye on things when it gets terribly cold out, which, unfortunately, will be soon.
The Cobalt has a readout for each tire and it's consistent with my hand-held digital gauge. The Sonata just warns when a tire is "low" and IIRC, the system allows for about 5lbs less than Hyundai's spec before it lights up.
The trucks are ancient enough to not have any TPMS stuff.
The trucks are ancient enough to not have any TPMS stuff.
The sensors in my 2011 Cruze also vary in accuracy. Two of them can be up to 4 psi off.
But, they've never falsely triggered the low-pressure warning.
But, they've never falsely triggered the low-pressure warning.
On my Impala, when cold the sensors are very close to any one of my "Accutire" gauges. But when hot, the sensors read about 2-3 lbs. lower than the gauges. Weird!
Though I think it's "cool" to see the tire pressure in the Driver Information Center, I still trust my gauges more.
Though I think it's "cool" to see the tire pressure in the Driver Information Center, I still trust my gauges more.
Originally Posted By: ExMachina
Originally Posted By: Garak
But, the darned things are so picky that, with a specified cold pressure of 33 pounds, they go off at like 30 pounds.
On some cars that threshold is settable. Yours do that?
Originally Posted By: Garak
I don't think so. At least there's no indication how to do so in the FSM, even if you have the fancy Nissan/Infiniti Consult machine. I just have resigned myself to keeping a good eye on things when it gets terribly cold out, which, unfortunately, will be soon.
Usually I'm OK on the BMW by just setting pressure to at least 4 psi over spec so it doesn't give me a yellow low-pressure warning when it turns cold! And so far I've not found any system that lets us set the threshold pressure for alarms, and I guess they don't want us controlling that. This TPMS situation is getting complicated, since many makes/models are involved. See: http://artsautomotive.com/publications/8-automotive/81-tires-tpms-tire-pressure-monitoring-system/ for the headaches tire change shops and customers are enduring.
Originally Posted By: Garak
But, the darned things are so picky that, with a specified cold pressure of 33 pounds, they go off at like 30 pounds.
On some cars that threshold is settable. Yours do that?
Originally Posted By: Garak
I don't think so. At least there's no indication how to do so in the FSM, even if you have the fancy Nissan/Infiniti Consult machine. I just have resigned myself to keeping a good eye on things when it gets terribly cold out, which, unfortunately, will be soon.
Usually I'm OK on the BMW by just setting pressure to at least 4 psi over spec so it doesn't give me a yellow low-pressure warning when it turns cold! And so far I've not found any system that lets us set the threshold pressure for alarms, and I guess they don't want us controlling that. This TPMS situation is getting complicated, since many makes/models are involved. See: http://artsautomotive.com/publications/8-automotive/81-tires-tpms-tire-pressure-monitoring-system/ for the headaches tire change shops and customers are enduring.
Originally Posted By: OVERKILL
Originally Posted By: hattaresguy
The pressures in my Ram are right on and it tells you the pressure of each tire as well which is nice.
Yup, same with my Charger.
Likewise on my sig car, manufactured in July 05. I have never even had to replace a battery. I do replace the seals when I change tires...
Originally Posted By: hattaresguy
The pressures in my Ram are right on and it tells you the pressure of each tire as well which is nice.
Yup, same with my Charger.
Likewise on my sig car, manufactured in July 05. I have never even had to replace a battery. I do replace the seals when I change tires...
Originally Posted By: stephen9666
The sensors in my 2011 Cruze also vary in accuracy. Two of them can be up to 4 psi off. But, they've never falsely triggered the low-pressure warning.
Maybe you got the same 2011 GM batch that I did. Their requirements for calibration quality-consistency is just too loose. I wonder if the TREAD Act law (in the U.S.) that forced cars to have these mentioned anything about minimum sensor calibration?
Originally Posted By: oldmaninsc
On my Impala, when cold the sensors are very close to any one of my "Accutire" gauges. But when hot, the sensors read about 2-3 lbs. lower than the gauges. Weird! Though I think it's "cool" to see the tire pressure in the Driver Information Center, I still trust my gauges more.
Depends on if its a cheap gauge, or a decent one, and even then, any single guage can be off, so average a few if you're interested. ... I'm not seeing the temperature differences in calibration offset you're seeing, and I don't know why a sensor would/can do that unless the sensor membrane is losing flexibility or has expansion/contraction sealing issues(???).
The sensors in my 2011 Cruze also vary in accuracy. Two of them can be up to 4 psi off. But, they've never falsely triggered the low-pressure warning.
Maybe you got the same 2011 GM batch that I did. Their requirements for calibration quality-consistency is just too loose. I wonder if the TREAD Act law (in the U.S.) that forced cars to have these mentioned anything about minimum sensor calibration?
Originally Posted By: oldmaninsc
On my Impala, when cold the sensors are very close to any one of my "Accutire" gauges. But when hot, the sensors read about 2-3 lbs. lower than the gauges. Weird! Though I think it's "cool" to see the tire pressure in the Driver Information Center, I still trust my gauges more.
Depends on if its a cheap gauge, or a decent one, and even then, any single guage can be off, so average a few if you're interested. ... I'm not seeing the temperature differences in calibration offset you're seeing, and I don't know why a sensor would/can do that unless the sensor membrane is losing flexibility or has expansion/contraction sealing issues(???).
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Originally Posted By: zrxkawboy
I've noticed on my '07 Silverado that the TPMS sensors are up to 2 psi different from the gauge.
That's about what I see on the Regal. My pencil gauge, and the Sears tire inflator, both read 34 psi. But the TPMS readout will be 31-32.
I've noticed on my '07 Silverado that the TPMS sensors are up to 2 psi different from the gauge.
That's about what I see on the Regal. My pencil gauge, and the Sears tire inflator, both read 34 psi. But the TPMS readout will be 31-32.
On my 2008 Grand Prix GXP my TPMS and manual gauge are pretty spot on. I like the fact it tells you each tires pressure in the info center, and has a large enough threshold each way so as to not trigger any false indicators. My TPMS I must say is aftermarket per the previous owner, so I can't speak for GM's original quality. On my wife's 2007 Trailblazer it's about 1 psi off, but we always have a sensor that sometimes stops communicating which is a pain. Dealer could never reproduce. Figures...
Originally Posted By: ExMachina
Originally Posted By: stephen9666
The sensors in my 2011 Cruze also vary in accuracy. Two of them can be up to 4 psi off. But, they've never falsely triggered the low-pressure warning.
Maybe you got the same 2011 GM batch that I did. Their requirements for calibration quality-consistency is just too loose. I wonder if the TREAD Act law (in the U.S.) that forced cars to have these mentioned anything about minimum sensor calibration?
Originally Posted By: oldmaninsc
On my Impala, when cold the sensors are very close to any one of my "Accutire" gauges. But when hot, the sensors read about 2-3 lbs. lower than the gauges. Weird! Though I think it's "cool" to see the tire pressure in the Driver Information Center, I still trust my gauges more.
Depends on if its a cheap gauge, or a decent one, and even then, any single guage can be off, so average a few if you're interested. ... I'm not seeing the temperature differences in calibration offset you're seeing, and I don't know why a sensor would/can do that unless the sensor membrane is losing flexibility or has expansion/contraction sealing issues(???).
I guess you missed the part in my post where I said ". . . when cold the sensors are very close to any one of my "Accutire" gauges." For that matter my cheap pencil and analog dial gauge also read within about .5 - 1 lb of each other and the 4 Accutire gauges, and one other no name digital gauge. Is that enough of an average? LOL
While the Accutire gauges may not be the most expensive in the world, they do appear to be fairly accurate and reliable. If I find a gauge to be consistently several pounds off, I usually throw it away.
I have no idea either why the difference between hot and cold on the sensor vs. the gauge issue, and to be honest haven't really spent that much time thinking about it - just pointing out my observation.
Originally Posted By: stephen9666
The sensors in my 2011 Cruze also vary in accuracy. Two of them can be up to 4 psi off. But, they've never falsely triggered the low-pressure warning.
Maybe you got the same 2011 GM batch that I did. Their requirements for calibration quality-consistency is just too loose. I wonder if the TREAD Act law (in the U.S.) that forced cars to have these mentioned anything about minimum sensor calibration?
Originally Posted By: oldmaninsc
On my Impala, when cold the sensors are very close to any one of my "Accutire" gauges. But when hot, the sensors read about 2-3 lbs. lower than the gauges. Weird! Though I think it's "cool" to see the tire pressure in the Driver Information Center, I still trust my gauges more.
Depends on if its a cheap gauge, or a decent one, and even then, any single guage can be off, so average a few if you're interested. ... I'm not seeing the temperature differences in calibration offset you're seeing, and I don't know why a sensor would/can do that unless the sensor membrane is losing flexibility or has expansion/contraction sealing issues(???).
I guess you missed the part in my post where I said ". . . when cold the sensors are very close to any one of my "Accutire" gauges." For that matter my cheap pencil and analog dial gauge also read within about .5 - 1 lb of each other and the 4 Accutire gauges, and one other no name digital gauge. Is that enough of an average? LOL
While the Accutire gauges may not be the most expensive in the world, they do appear to be fairly accurate and reliable. If I find a gauge to be consistently several pounds off, I usually throw it away.
I have no idea either why the difference between hot and cold on the sensor vs. the gauge issue, and to be honest haven't really spent that much time thinking about it - just pointing out my observation.
Originally Posted By: ExMachina
Originally Posted By: stephen9666
The sensors in my 2011 Cruze also vary in accuracy. Two of them can be up to 4 psi off. But, they've never falsely triggered the low-pressure warning.
Maybe you got the same 2011 GM batch that I did. Their requirements for calibration quality-consistency is just too loose. I wonder if the TREAD Act law (in the U.S.) that forced cars to have these mentioned anything about minimum sensor calibration?
Originally Posted By: oldmaninsc
On my Impala, when cold the sensors are very close to any one of my "Accutire" gauges. But when hot, the sensors read about 2-3 lbs. lower than the gauges. Weird! Though I think it's "cool" to see the tire pressure in the Driver Information Center, I still trust my gauges more.
Depends on if its a cheap gauge, or a decent one, and even then, any single guage can be off, so average a few if you're interested. ... I'm not seeing the temperature differences in calibration offset you're seeing, and I don't know why a sensor would/can do that unless the sensor membrane is losing flexibility or has expansion/contraction sealing issues(???).
Load cells are highly dependent on temperature.
Originally Posted By: stephen9666
The sensors in my 2011 Cruze also vary in accuracy. Two of them can be up to 4 psi off. But, they've never falsely triggered the low-pressure warning.
Maybe you got the same 2011 GM batch that I did. Their requirements for calibration quality-consistency is just too loose. I wonder if the TREAD Act law (in the U.S.) that forced cars to have these mentioned anything about minimum sensor calibration?
Originally Posted By: oldmaninsc
On my Impala, when cold the sensors are very close to any one of my "Accutire" gauges. But when hot, the sensors read about 2-3 lbs. lower than the gauges. Weird! Though I think it's "cool" to see the tire pressure in the Driver Information Center, I still trust my gauges more.
Depends on if its a cheap gauge, or a decent one, and even then, any single guage can be off, so average a few if you're interested. ... I'm not seeing the temperature differences in calibration offset you're seeing, and I don't know why a sensor would/can do that unless the sensor membrane is losing flexibility or has expansion/contraction sealing issues(???).
Load cells are highly dependent on temperature.
Originally Posted By: ExMachina
Usually I'm OK on the BMW by just setting pressure to at least 4 psi over spec so it doesn't give me a yellow low-pressure warning when it turns cold!
That usually gets me by, unless something is terribly amiss outside, like -40.
Usually I'm OK on the BMW by just setting pressure to at least 4 psi over spec so it doesn't give me a yellow low-pressure warning when it turns cold!
That usually gets me by, unless something is terribly amiss outside, like -40.
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