Tire psi

[jgaudet99]

Thanks for all the help so far!

 

I did try right from 2026 right down to 2021, and only from 2023 down lets me select the option for tire psi change, but I get the vehicle not supported error!

 

I'll definitely try it under Chevrolet after work today, and I'll get the sensor number from gm for my truck tire sensors. And I'll let you know if it works for me under Chevrolet!

 

And if that doesn't work, I'm going to guess that what @Atlas said about maybe I have a different body control module could be true!

 

[jgaudet99]

I had a little bit of time before I left for work this morning, so I plugged the scanner back in, and I selected Chevrolet Silverado instead of GMC Sierra, and the very first option was for a 2026 so I selected that one and I seen at the bottom it had the option for psi change unlike in the 2026 GMC Sierra, I selected that option and it took a little longer than the usual vehicle not supported, and sure enough I got into it, and it let my change the psi values.. I no longer have the low psi warning light!

 

Thank you for recommending me to try it under Chevrolet instead! I can confirm this device does work for a 2026 GMC Sierra 2500 hd 6.6 diesel  just have to select Chevrolet Silverado instead of GMC Sierra.

 

Maybe I'll contact Autel and let them know of that issue and maybe they will fix it for the GMC option  because some people probably return the scanner due to it not working under GMC Sierra.

[Chuck FB]

48 minutes ago, jgaudet99 said:

I had a little bit of time before I left for work this morning, so I plugged the scanner back in, and I selected Chevrolet Silverado instead of GMC Sierra, and the very first option was for a 2026 so I selected that one and I seen at the bottom it had the option for psi change unlike in the 2026 GMC Sierra, I selected that option and it took a little longer than the usual vehicle not supported, and sure enough I got into it, and it let my change the psi values.. I no longer have the low psi warning light!

 

Thank you for recommending me to try it under Chevrolet instead! I can confirm this device does work for a 2026 GMC Sierra 2500 hd 6.6 diesel  just have to select Chevrolet Silverado instead of GMC Sierra.

 

Maybe I'll contact Autel and let them know of that issue and maybe they will fix it for the GMC option  because some people probably return the scanner due to it not working under GMC Sierra.

 

Glad that worked, and in this case that is all on Autel for somehow dropping the ball for not updating the GMC section properly. 

 

I believe in the basic section or unless it is in the advanced, when one does a check of lets say individual sensors for what the pressure is ( and it shows a temperature as well ) , I think it picks up on what the model number of the sensor is in a certain section where you choose "OE" sensor or at least mine is telling me what the model number is and matches to what they actually are and that is the number I quoted in a prior post. 

 

I don't recall now if I had said prior that I discovered with my truck anyway that no matter how low I set the placard pressure for the rear tires, if the physical pressure is under 35 psi and I drive it for about 15 miles the pressure warning will come on for one or both rear tires. I am speculating that there is something else in the trucks system that over rides the placard pressure setting once it drops below that minimum pressure to run a metric LT tire at. The weird thing is it does not trigger right away after driving a shorter distance, it took that longer drive for it to trigger. Just something to keep in mind if you were experimenting with pressures below 35 pounds for a tire designed for lower pressures ( larger than stock floatation series tires ) and not being overloaded of course. 

[jgaudet99]

10 hours ago, Chuck FB said:

 

Glad that worked, and in this case that is all on Autel for somehow dropping the ball for not updating the GMC section properly. 

 

I believe in the basic section or unless it is in the advanced, when one does a check of lets say individual sensors for what the pressure is ( and it shows a temperature as well ) , I think it picks up on what the model number of the sensor is in a certain section where you choose "OE" sensor or at least mine is telling me what the model number is and matches to what they actually are and that is the number I quoted in a prior post. 

 

I don't recall now if I had said prior that I discovered with my truck anyway that no matter how low I set the placard pressure for the rear tires, if the physical pressure is under 35 psi and I drive it for about 15 miles the pressure warning will come on for one or both rear tires. I am speculating that there is something else in the trucks system that over rides the placard pressure setting once it drops below that minimum pressure to run a metric LT tire at. The weird thing is it does not trigger right away after driving a shorter distance, it took that longer drive for it to trigger. Just something to keep in mind if you were experimenting with pressures below 35 pounds for a tire designed for lower pressures ( larger than stock floatation series tires ) and not being overloaded of course. 

That's good to know, but I don't think I'll even be running them under 45 in the rear  unless it's on the sand or something but will only be for a short distance anyways! 

 

I didn't read all the instructions in the booklet yet, but do you know let's say I set the rear psi on the placard to 45, will the warning light come on soon as it drops under 45 or is there a percentage it has to drop from the set value before the warning light is triggered?

[Chuck FB]

23 minutes ago, jgaudet99 said:

That's good to know, but I don't think I'll even be running them under 45 in the rear  unless it's on the sand or something but will only be for a short distance anyways! 

 

I didn't read all the instructions in the booklet yet, but do you know let's say I set the rear psi on the placard to 45, will the warning light come on soon as it drops under 45 or is there a percentage it has to drop from the set value before the warning light is triggered?

 

I will admit I haven't experimented much with pressure drops beyond the numbers I put in and part of that is that the numbers I used are fairly low and then found out it would trigger regardless at that 35 psi. Having said that I had tried before had changed the placard pressures and being that I have a 1 ton set to 80 on the placard for the rear I believe it triggered close to 60, the front I don't recall now for sure but thought maybe it could get close to 45 from that factory 60 placard pressure. So I never did figure out if it was a number of psi from placard pressure to the alarm or a percentage of the total placard number as some figured it was like a 25% drop from placard pressure would trigger it. So as to try and answer your question, I believe I set the placard pressure on the front to 47 or so and while I run the front tires at 40, they have dipped below that some if its colder and I haven't put "winter air" in yet and never once have had the front alarm go off. I would say that the answer your looking for is no, that if you set your placard pressure to 45, you have a certain amount of room to drop below that pressure before the alarm will go off. 

 

The pressures you decide to run in your truck, that ends up being what makes sense to you based on what your carrying in your truck or if towing, then have to bump them back up to something that will carry the load in the rear and the fronts typically left at the same pressure. It all comes down to that chart I put the link to and using an accurate roadside scale to be your guide, both unloaded and then loaded to know your minimum safe pressures. 

 

I just wish GM would allow a person to change the readings for the tire pressures to the English system of pounds as I have to look at that goofy metric reading that will never ever jive in my head and will go over and change it just to figure out what they are if need be and then change it back. 

[jgaudet99]

5 hours ago, Chuck FB said:

 

I will admit I haven't experimented much with pressure drops beyond the numbers I put in and part of that is that the numbers I used are fairly low and then found out it would trigger regardless at that 35 psi. Having said that I had tried before had changed the placard pressures and being that I have a 1 ton set to 80 on the placard for the rear I believe it triggered close to 60, the front I don't recall now for sure but thought maybe it could get close to 45 from that factory 60 placard pressure. So I never did figure out if it was a number of psi from placard pressure to the alarm or a percentage of the total placard number as some figured it was like a 25% drop from placard pressure would trigger it. So as to try and answer your question, I believe I set the placard pressure on the front to 47 or so and while I run the front tires at 40, they have dipped below that some if its colder and I haven't put "winter air" in yet and never once have had the front alarm go off. I would say that the answer your looking for is no, that if you set your placard pressure to 45, you have a certain amount of room to drop below that pressure before the alarm will go off. 

 

The pressures you decide to run in your truck, that ends up being what makes sense to you based on what your carrying in your truck or if towing, then have to bump them back up to something that will carry the load in the rear and the fronts typically left at the same pressure. It all comes down to that chart I put the link to and using an accurate roadside scale to be your guide, both unloaded and then loaded to know your minimum safe pressures. 

 

I just wish GM would allow a person to change the readings for the tire pressures to the English system of pounds as I have to look at that goofy metric reading that will never ever jive in my head and will go over and change it just to figure out what they are if need be and then change it back. 

My truck is a ¾ ton but my placard also says 80 for the rear tires, I think I might have the upgraded suspension to the 3500 series maybe.

 

I put my air down to 60 and the light was still on, and there was no way I was putting over 60 psi in the rear empty and not towing because I knew the actual number Toyo gave me and I didn't wanna ruin the center of my tires!

 

And you actually can change it in the settings from metric or is and it will show kph or mph then when you go into your tire settings it will be either psi or kpa, but it would be nice to just change it directly on the tire psi page 

[Chuck FB]

2 hours ago, jgaudet99 said:

My truck is a ¾ ton but my placard also says 80 for the rear tires, I think I might have the upgraded suspension to the 3500 series maybe.

 

I put my air down to 60 and the light was still on, and there was no way I was putting over 60 psi in the rear empty and not towing because I knew the actual number Toyo gave me and I didn't wanna ruin the center of my tires!

 

And you actually can change it in the settings from metric or is and it will show kph or mph then when you go into your tire settings it will be either psi or kpa, but it would be nice to just change it directly on the tire psi page 

 

You must have that upgraded gvw package which is only available or at least was in 2025 with the diesel engine for the 3/4 ton and that gave the truck physically the larger 12.0 ring gear rear diff and the 3500 rear spring pack. There is a difference in what the diff housing looks like externally as one tell tale and also your truck should have the upper overload spring pack and the frame pads that the pack goes up against. 

 

The pressure the tpms system kicks the alarm in on a stock setting truck, that is a good question and was just from what I recall but I doubt I made any notes on it as I knew for the rear that it was not at all what I was after regardless either. Being that you have a diesel and if running on stock tires the minimum pressure on an empty truck seems to be around 50 psi from hearing of those that have weighted the front axle but the rear axle is very similar in weight to a gas truck and again a near empty truck on the rear could go down to 35 pounds at minimum. However the weigh scale is the proper way to know for sure as a guide. 

 

As to changing the readings on the dash from metric to the US measuring system, oh yes that is done easily but what I was attempting to explain was that I can't pick and choose items I want to have in US and those I still want in the metric system at the same time as its either all or none. For example lets say you drove into Canada and switched your dash over to metric so your speedometer read in km an hour, well then your reading kilopascals on your tpms readout and your wife looks over and says what the hell is that saying in the tpms screen and you say "darned if I know, I think its Chinese" !

[jgaudet99]

36 minutes ago, Chuck FB said:

 

You must have that upgraded gvw package which is only available or at least was in 2025 with the diesel engine for the 3/4 ton and that gave the truck physically the larger 12.0 ring gear rear diff and the 3500 rear spring pack. There is a difference in what the diff housing looks like externally as one tell tale and also your truck should have the upper overload spring pack and the frame pads that the pack goes up against. 

 

The pressure the tpms system kicks the alarm in on a stock setting truck, that is a good question and was just from what I recall but I doubt I made any notes on it as I knew for the rear that it was not at all what I was after regardless either. Being that you have a diesel and if running on stock tires the minimum pressure on an empty truck seems to be around 50 psi from hearing of those that have weighted the front axle but the rear axle is very similar in weight to a gas truck and again a near empty truck on the rear could go down to 35 pounds at minimum. However the weigh scale is the proper way to know for sure as a guide. 

 

As to changing the readings on the dash from metric to the US measuring system, oh yes that is done easily but what I was attempting to explain was that I can't pick and choose items I want to have in US and those I still want in the metric system at the same time as its either all or none. For example lets say you drove into Canada and switched your dash over to metric so your speedometer read in km an hour, well then your reading kilopascals on your tpms readout and your wife looks over and says what the hell is that saying in the tpms screen and you say "darned if I know, I think its Chinese" !

Yes that's right, it's the upgrade that includes the overload spring and all that stuff.

 

Someday when I'm empty and going by a scale I'm going to stop in and get some weight readings.

 

Exactly  you should have the ability to change individual settings, in in Canada so I'm driving with kph but then I'm stuck with kpa when I want psi lol

 

 

[Chuck FB]

49 minutes ago, jgaudet99 said:

Yes that's right, it's the upgrade that includes the overload spring and all that stuff.

 

Someday when I'm empty and going by a scale I'm going to stop in and get some weight readings.

 

Exactly  you should have the ability to change individual settings, in in Canada so I'm driving with kph but then I'm stuck with kpa when I want psi lol

 

 

 

I just can't think of the exact term GM uses for that higher gvw package without looking at the website but basically sort of a trailering package and I imagine it may also have been created to skirt around the licensing fee differences between a3/4 and 1 ton that apply in some states although ironically I believe in some states its the reverse that a 1 ton is the cheaper truck to license over a 3/4 ton. It makes no difference here in Alberta but oddly enough a 1 ton through my insurance company is a bit cheaper to insure over a 3/4 ton as its based on the insurance statistics they generate. 

 

For sure when ever you do have the chance to weigh your truck and to be fair, try to have the fuel tank full or nearly so rather than give yourself a false sense of the truck being lighter by having an almost empty tank. 

 

In my other comment I was mentioning stock sized tires and partly in case someone was reading this and thinking they could lower their pressure down to what your aftermarket tires are able to do with your empty truck as that is a vastly different picture in the leeway you have to play with for running minimum pressures while remaining safe. I will say also that its easy to see from reactions of truck owners that may have been more used to owning a half ton in the past or a car and be it on a forum like this or in person etc that they get so wrapped up in that placard pressure sticker that they can't get their head wrapped around the fact that an HD truck due to how much it can carry can also vary the tire pressures drastically lower than those pressures ( typically more so for the rear axle on stock sized tires ) when empty vs some car that isn't made to carry much so the tire pressures can't be lowered since it needs almost that much pressure just to carry the empty car. 

 

If I ever do find myself in the states with this truck, I will only be too happy to switch it over to the US measuring system as then I will understand all the dash readings. The only thing that is off for me slightly with US measurements is US miles per gallon as I grew up with the Imperial gallon and to this day up here anyway speak in Imperial miles per gallon ( I don't do that on this forum though as that would confuse everyone for no good reason ). 

[newdude]

1 hour ago, Chuck FB said:

 

I just can't think of the exact term GM uses for that higher gvw package without looking at the website but basically sort of a trailering package and I imagine it may also have been created to skirt around the licensing fee differences between a3/4 and 1 ton that apply in some states although ironically I believe in some states its the reverse that a 1 ton is the cheaper truck to license over a 3/4 ton. It makes no difference here in Alberta but oddly enough a 1 ton through my insurance company is a bit cheaper to insure over a 3/4 ton as its based on the insurance statistics they generate. 

 

For sure when ever you do have the chance to weigh your truck and to be fair, try to have the fuel tank full or nearly so rather than give yourself a false sense of the truck being lighter by having an almost empty tank. 

 

In my other comment I was mentioning stock sized tires and partly in case someone was reading this and thinking they could lower their pressure down to what your aftermarket tires are able to do with your empty truck as that is a vastly different picture in the leeway you have to play with for running minimum pressures while remaining safe. I will say also that its easy to see from reactions of truck owners that may have been more used to owning a half ton in the past or a car and be it on a forum like this or in person etc that they get so wrapped up in that placard pressure sticker that they can't get their head wrapped around the fact that an HD truck due to how much it can carry can also vary the tire pressures drastically lower than those pressures ( typically more so for the rear axle on stock sized tires ) when empty vs some car that isn't made to carry much so the tire pressures can't be lowered since it needs almost that much pressure just to carry the empty car. 

 

If I ever do find myself in the states with this truck, I will only be too happy to switch it over to the US measuring system as then I will understand all the dash readings. The only thing that is off for me slightly with US measurements is US miles per gallon as I grew up with the Imperial gallon and to this day up here anyway speak in Imperial miles per gallon ( I don't do that on this forum though as that would confuse everyone for no good reason ). 

 

 

Max Trailering Package.  RPO code NHT.   includes 3500 HD Frame, 3500 HD Leaf Springs, 12" Rear axle and 3500 HD Shock Package.

 

GVWR goes to 11,750lbs for crew cab standard box 4x4, 11,900lbs for crew cab long box 4x4.  2WD crew standard is 11,500lbs, 11,550lbs crew long 2wd, and 11,450lbs on regular and double cab 4x4.    

 

There is also NHT on 1 ton dually regular cab 2WD.  includes 3500 HD Frame, 3500 HD Leaf Springs, (F60) Heavy Duty Front Spring/Camper Package, 12" Rear axle, 3500 HD Shock Package, and Z6A Gooseneck / 5th Wheel Prep provisions with bed stamped holes and caps.  GVWR of 14,000lbs.  

 

Edited Thursday at 02:30 PM by newdude

[Chuck FB]

1 hour ago, newdude said:

 

 

Max Trailering Package.  RPO code NHT.   includes 3500 HD Frame, 3500 HD Leaf Springs, 12" Rear axle and 3500 HD Shock Package.

 

GVWR goes to 11,750lbs for crew cab standard box 4x4, 11,900lbs for crew cab long box 4x4.  2WD crew standard is 11,500lbs, 11,550lbs crew long 2wd, and 11,450lbs on regular and double cab 4x4.    

 

There is also NHT on 1 ton dually regular cab 2WD.  includes 3500 HD Frame, 3500 HD Leaf Springs, (F60) Heavy Duty Front Spring/Camper Package, 12" Rear axle, 3500 HD Shock Package, and Z6A Gooseneck / 5th Wheel Prep provisions with bed stamped holes and caps.  GVWR of 14,000lbs.  

 

 Uh yes, that's the name of the package. It doesn't quite bring it up to 1 ton specs unfortunately and imagine they have to do that for a numbers reason rather than a physical one. 

 

Am I correct though that the Max Trailer Package and therefore the 12" rear is only available on the Duramax and not on any of the L8T 3/4 ton trucks ( and that the same 11.5 rear axle center section is used on the 3/4, 1 ton SRW and even 1 ton dually gas version ) ?

 

I'd also be curious to know if the wheel bearings are the same on a SRW configuration between an 11.5 vs the 12" diff as I assume parts would show that up but may not explain what the difference is if indeed there was a physical difference. 

Edited Thursday at 03:55 PM by Chuck FB

[newdude]

4 hours ago, Chuck FB said:

 Uh yes, that's the name of the package. It doesn't quite bring it up to 1 ton specs unfortunately and imagine they have to do that for a numbers reason rather than a physical one. 

 

Am I correct though that the Max Trailer Package and therefore the 12" rear is only available on the Duramax and not on any of the L8T 3/4 ton trucks ( and that the same 11.5 rear axle center section is used on the 3/4, 1 ton SRW and even 1 ton dually gas version ) ?

 

I'd also be curious to know if the wheel bearings are the same on a SRW configuration between an 11.5 vs the 12" diff as I assume parts would show that up but may not explain what the difference is if indeed there was a physical difference. 

 

NHT is diesel only, correct.  

 

The GVWRs for NHT on 3/4 ton bring them to the same numbers as many of the 2WD 1 tons.  A crew 4x4 standard 3/4 with NHT is 11,750lbs, a 1 ton same cab/box/4x4 is 12,100lbs.  

 

Hubs and hub bearings are the same for 11.5" and 12" axles.  Housing, diff carrier and ring/pinion are larger for the 12".

 

All gas use the 11.5" axle, 3/4, 1 ton and 1 ton DRW. 

Edited Thursday at 08:00 PM by newdude