Air Pressure Monitor

[Mike2500HD]

Any one else out there think 80psi in a 245-75-16 tire on a 3/4 ton truck is too much running mostly empty? And find out that when you lower it to 50 psi or so the info center warns you, and then onstar sends you emails? I use my 07 2500HD for getting to work more than anything. Towing the boat....5,000lbs...and a bit of side work. so most of the time I'm empty. Skinny 245's over pressured at 80 psi for max load will leave you with squeeks and rattles and likely in a ditch in the rain. So I droped them to 50 then kept bringing them up till the warning went out. 65 in the rear. the fronts are ok at 50. the dealer says they might have some way to re-program the computer but they suggested it would cost $300.00! screw that. I want the fronts and rears both programmed as fronts. that way I can run 50 all around and fill to higher press. when I'm towing. And what if I choose other tires in the future(very likely) that require less pressure? I was a trucker for 25 years hauling heavy oversize loads all over the country so I think I'm qualified to monitor my tires. I like the technology but I think I should be able to set it where I want and then have it warn me if it drops while I'm driving. Any thoughts?

[ursandal]

I agree!! I asked a service manager about it and he said they could change the tolerances but said due to liability issues they wouldn't touch it...Damn lawyers!!! All I asked for was to match the rears to the front (60psi) and they still said "no".

 

I did get new tires but stayed with a LR E so I could keep the pressures up. I know some folks run a D range but with this TPMS they'll forever get the warning lights/chimes.

[robertbick]

80 psi? My door label specifies 50psi front and 72psi rear. I even think the 72 rear is too high when running empty which I also do most of the time. I keep my fronts at 50 and have the rears at 68. How low can I go on the rears without triggering the DIC warning?

[ursandal]

80 psi? My door label specifies 50psi front and 72psi rear. I even think the 72 rear is too high when running empty which I also do most of the time. I keep my fronts at 50 and have the rears at 68. How low can I go on the rears without triggering the DIC warning?

 

 

I think you have the 17" tire option so the recommended pressures are slightly different. Not sure where the alarm goes off, I'd guess around 10-15% down from the recommended pressure or 61-65 psi in your case. Best way to find out would be to air down in 5 psi increments until it goes off.

 

Al

[dewfpo]

The way the TPMS is set up it sucks. 80 psi when empty is way to hard.... on you, on your truck. You might as well be running on solid rubber tires. I run 40-45 when empty or not towing but I don't have a TPMS.

 

DEWFPO

[robertbick]

I think you have the 17" tire option so the recommended pressures are slightly different. Not sure where the alarm goes off, I'd guess around 10-15% down from the recommended pressure or 61-65 psi in your case. Best way to find out would be to air down in 5 psi increments until it goes off.

 

Al

 

yeah, I have the 17's. Thanks!

[chrisb1]

2008 GMC 2500HD with 17 inch rims. I run 60psi on all four for daily running around.

I get no error message on dashboard but Onstar does email me with a low pressure warning on the two rears.

[Mike2500HD]

80 psi? My door label specifies 50psi front and 72psi rear. I even think the 72 rear is too high when running empty which I also do most of the time. I keep my fronts at 50 and have the rears at 68. How low can I go on the rears without triggering the DIC warning?

 

I dropped mine to 65 and the light is out most of the time. Colder temps will bring the light on until the tires warm up. Actually I've gotten used to the damn light being on and I might just go ahead and run front and rear at 50. screw the light...screw the lawyers...And what if you run 80 psi and skid off the road in the rain? I suppose a well thought out lawsuit could change their mind.

[Mike2500HD]

I agree!! I asked a service manager about it and he said they could change the tolerances but said due to liability issues they wouldn't touch it...Damn lawyers!!! All I asked for was to match the rears to the front (60psi) and they still said "no".

 

I did get new tires but stayed with a LR E so I could keep the pressures up. I know some folks run a D range but with this TPMS they'll forever get the warning lights/chimes.

 

Yea I was thinking the lawyers would have somethinf like that to say. I wonder if you complained constantly in writing that the pressure was too high and was unsafe...as it definately is..and then slid off the road if you could bring a suit against them...and what about people with pre 07 vehicles? I drove the truck at all pressures. Its not comfortable or safe with 65 front and 80 rear. It wonders around, jumps and bounces over bumps and generally feels squirley. It felt best with 50 front and rear. A freind who is a BMW service MGR. said the BMW's have owner resetable pressures. The guys with the 17" wheels might not have the same issue either. Wider tires with less sidewall probably dont feel as unsafe with the recomended pressure. Whenever any one of us comunicates with GM about it we should always refere to it as the "unsafe" over inflated recomended pressure. That 80 psi is for max rated load. Running empty the rear tires have LESS weight on them than an econobox car!

[Mike2500HD]

The way the TPMS is set up it sucks. 80 psi when empty is way to hard.... on you, on your truck. You might as well be running on solid rubber tires. I run 40-45 when empty or not towing but I don't have a TPMS.

 

DEWFPO

 

Exactly...but you know what your doing..the entire issue is because of soccer moms in Excursions with 18 psi in one tire and going 90 on the interstate cluelessly until it blows! So big brother has this great idea...and it is a great idea...but they screw it up so instead of gaining a safety asset we get a constant worthless light on the dash to ignore...but if you roll they will have it on record that you ran too low pressure....

[drvideo]

Due to production line shortages my '07 2500HD was delivered with 245/75R16's. Air pressure on delivery was 80 lbs. I discussed this with the service manager and he didn't seem to understand the concept of matching load to pressure. After some tense words were exchanged, he agreed to reprogram the TPMS, but stated the lowest he could set it was 50 lbs. I now run 45 lbs both front and rear; no dash warning, but OnStar sends me a yellow "Warning" every month. What ever happened to the concept of individual personal responsibility ???

[Mike2500HD]

Due to production line shortages my '07 2500HD was delivered with 245/75R16's. Air pressure on delivery was 80 lbs. I discussed this with the service manager and he didn't seem to understand the concept of matching load to pressure. After some tense words were exchanged, he agreed to reprogram the TPMS, but stated the lowest he could set it was 50 lbs. I now run 45 lbs both front and rear; no dash warning, but OnStar sends me a yellow "Warning" every month. What ever happened to the concept of individual personal responsibility ???

 

I'm impressed you were able to get them to reprogram. Your the first I've heard. Most people are told some crap about liability. Yea I want to run 50 all around. Except when I need to tow the boat. Actually even with the boat I wont be anywhere near Max load. GM seems to have their head up their ass about this. I was in the trucking buisness for 25 years hauling heavy oversize loads and machinery. I know plenty about tires and loads. Also what did they charge to re-program for you? All I want is to have all 4 tires set at 50psi. Or at least what ever the fronts are set at as this has been allowing 50 psi without the light. One more thing. If they dont understand load vs pressure then why is front pressure set at 65 and rear at 80 from the factory? M.R.

[Colorado Kid]

This probably won't help those of you with newer trucks, but on my '04 the proceedure for calibrating the TPS is in the manual. If you follow the proceedure on anything but the coldest day of the year you end up with low tire temperature warning system (any time it's more than abotu 20 degrees colder than when you calibrated it the warning will go off). This made for a lot of phone calls from Mrs. Kid. I learned to calibrate per the published proceedure at a tire pressure about 5 psi below what I actually want to run, then add the 5 psi to each tire after the calibration. As a result it's been about 45,000 miles since the light, chimes and message last came on.

 

 

If your manual has a proceedure for calibrating the TPS after a tire rotation you can follow my lead and fix it. I suspect that the later models are more sophisticated and can some how tell where the wheel is on the vehicle and its PSI directly. My '04 can only tell if PSI has decreased, and which sensor is squawking . . . if you rotate the tires without telling it where you put the sensors it will send you looking where the wheel/tire used to be instead of where it is.

[sheikss]

I called GM today and started complaining calling GM a bunch of idiots. I told them this was unsafe and that any tire company would tell them this. I also got told by the dealership that they would not fix it, due to it being unsafe. I actually had a rear tire blow on me about a month after I got the truck. The dealership didn't even have a replacement tire so I had to buy from and tire shop. Of course gm wouldn't pay for any of the repairs. Also my wheel weights won't stay on the rear wheels due to the 80 psi tire pressure. If you guys haven't driven your truck on a dirt road yet then I suggest you don't. My truck is extremely unstable on dirt roads. I told the lady on the phone that all of these problems have taked place at 50mph and below, and if I have a tire blow out again then GM can expect a phone call from a lawyer. I asked the dealership how they are selling lifted HD trucks with 20"+ rims that say max 60 psi and they wouldn't answer me. They defianantly didn't like it when I asked if the aftermarket rims load rating matched the factory rim load rating. I've heard some dealerships will change the settings others won't. I have also read that guys take a pipe place some end caps on it with tpms sensors in it and pressurize it to fool the system.

[sonjaab]

My TPMS went nuts months ago and I have had the warning light and low

tire pressure message bugging me ever since. So now that snowplowing

duty is over and the boats are in the water off to the dealer it went !

 

Figured I would have them replace the junk wiper blades too that have

came apart several times during hours of use during snowplowing duty

along with having them note a scratched up windsheild from same junk

blades on the repair order so thAT may also be replaced soon (on GMs

dime BTW!).

 

Anyhoo..After reading others stories of the dealer not wanting to reprogram

the TPMS for a lower pressure I must of got lucky or the tech screwed up!

I note that all my tires were aired down to 45 psi and the TPMS shows 45

psi. I do know that my 245/75-16 should be (and were) set at 50 frt.

80 rear when I dropped it off as per specs.

My ride is a lot better and no more "bouncing bed" at 45 psi.

I just wonder what will happen if and when I go to tow and air up to the

50/80 pressures?????

 

Good thing I got plenty of warranty left !!!!!!!!!!