Tire pressures round 2

rjgvt · March 7, 2024

A while back I set my tire pressures to 55 psi front and rear. Door sticker is 60 psi Front and 70 psi Rear. I recently had my truck weighed and decided to set them to 51 psi for all 4 tires with a little leeway if the temp dropped. After I got done and started up the truck, I got an email and text from Onstar to add air to my rear tires. I ignored it as the TPMS sensor error has not come on yet. It's been 3 days since I adjusted the pressures, no TPMS error. If the tires are warmed up and the rear pressures are 55 psi or more, no Onstar alerts.

The myGMC app shows orange if the front tires are under 55 psi and the rears under 60 or 65 psi. Not sure what it takes to get the TPMS error to come on but not going to lower the pressures any lower than 50 psi. The ride is good but as the average temps rise, I will watch the tire pressures and not make any adjustments until it gets over 55 psi.

bruceb58 · March 7, 2024

It's too bad GM doesn't have something like Ford's Forscan to change the limits. This would be an easy change with Forscan.

rjgvt · March 8, 2024

I can change the parameters through the OBD II with an Autel TS508 but haven’t done it yet since I don’t get a TPMS error on the DIC. When I did do a “read” with the Autel, it read -17 psi for both front and rear. I was expecting to see actual pressure readings like 60 and 70 psi. Not sure if it’s looking for -17 psi for the TPMS error. One day I’ll change the parameters and see what happens.

bruceb58 · March 8, 2024

I have the Kingbolen K10 scanner. When my truck actually arrives, I may play with it.

rjgvt · March 9, 2024

Got my Autel TS508 out today and attempted to change the tire pressure placard values to 60 front and 60 rear using the OBD II cable. I chose one of the 2023 GMC Sierras. It forces to do both. It said it was a success but when I "read" the parameters with the Autel, it still read -17 psi for front and rear.

Decided to do an update to the Autel, there were several. Before the update,it only showed GMC Sierras made in 2023 or before. After the update, it now shows 2024 GMC Sierras but they don't show the tire placard option. I went back out to my truck did the read function again and it read 60 psi front/60 psi rear. myGMC app updated to Front 60 psi / Rear 60 psi. The tire pressures on the app were orange as three of the values were less than 55 psi.

Changed the tire pressure placard values to 55 psi. Was able to read the values with the Autel right away. The update did the trick. Drove my truck down my driveway and back in the garage. myGMC app updated and no more orange tire pressure values.

EDIT: Autel's website says that all vehicles do not support the tire pressure placard value change function. Glad mine worked.

Edited March 9, 2024 by rjgvt

kylant · February 22

i just updated my Autel TS508 to the latest software. under the 24-25 gmc sierra sensors, there is no tire type/pressure selection option. there is for up to 2023. looks like the sensors may be the same part number.

can the 24-25 trucks be programmed using the 2023 setting in the tool?

thanks

newdude · February 22

6 minutes ago, kylant said:

i just updated my Autel TS508 to the latest software. under the 24-25 gmc sierra sensors, there is no tire type/pressure selection option. there is for up to 2023. looks like the sensors may be the same part number.

can the 24-25 trucks be programmed using the 2023 setting in the tool?

thanks

No. The TPM system changed on the 2024 HD to an auto learning system. Sensors are the same 433mHz frequency but are set up differently for the auto learn.

Programming a sensor for a 2023 and sticking it in a 2024 will not work.

Pryme · February 22

I wonder how much faster the tires will wear running such low psi in a 7200-8k pound truck? I’ve never thought to run less than stock pressure in my tires.

newdude · February 22

14 minutes ago, Pryme said:

I wonder how much faster the tires will wear running such low psi in a 7200-8k pound truck? I’ve never thought to run less than stock pressure in my tires.

I'd say it depends. Running 45-50psi would be hard on them. 60psi all around they'd probably wear fine. I used to run my HDs at 60psi all the way around empty. Got 50k miles out of a set of Firestone Transforce AT at that but that was on a 2004 gas HD regular cab 4x4, BUT, that generation was a LOT lighter than the new ones. Maybe 5600lbs? A 2025 Duramax 1500 Trail Boss 6ft 6in box is 5450lbs for comparison to how light the GMT-800 HDs were.

Edited February 22 by newdude

vucelick · February 22

My 2001 2500hd extended cab, long bed 8.1/allison weighed 6777 lbs with me in it.

kylant · February 22

52 minutes ago, newdude said:

No. The TPM system changed on the 2024 HD to an auto learning system. Sensors are the same 433mHz frequency but are set up differently for the auto learn.

Programming a sensor for a 2023 and sticking it in a 2024 will not work.

is it not possible to reduce the psi thresholds on the 2024-25 trucks?

kylant · February 22

39 minutes ago, Pryme said:

I wonder how much faster the tires will wear running such low psi in a 7200-8k pound truck? I’ve never thought to run less than stock pressure in my tires.

it's all about the load tables for the specific tire. those are usually posted by the tire manufacture

newdude · February 22

2 hours ago, kylant said:

is it not possible to reduce the psi thresholds on the 2024-25 trucks?

Perhaps I misread your question. I thought you were talking about programming sensors.

Another JR · February 22

5 hours ago, kylant said:

it's all about the load tables for the specific tire. those are usually posted by the tire manufacture

Yes, and those load tables are pretty much linear for psi/load in the top 1/3 of the weight range. The empty rear axle weight of my 3500 is 3260lbs, and the rear gross axle rating is 7250 lbs. No way is the truck sticker recommended 80 psi the right pressure for that 45% load. On the other hand, 40 psi isn’t the right answer for highway use either. 50 to 60 would be fine as far as heating and wear, but I have mine down against my TPMS limits at 63 or so when empty. When my 1800 lbs truck camper is on I go to 65-67. Wear is looking good on the OEM Michelins so far.

AndrewF · February 23

I don’t think the psi alert set points can be changed for the 24/25 trucks until aftermarket companies catch up and have tuning options available for Global B.