Stupid TPMS!!

[Grit_dog]

The new GM 1500s must have a lower threshold now! Just rotated the tires on my 2020 1500 Chebbie and set the rears (which are still reading front position and may be the issue but requires a re-learn tool to change) to 32psi cold. Truck is a pavement princess that is mostly driven empty, no load.
My old 2016, I recall didn't trip the low pressure light until > 25psi. I know I could air down for winter driving to under 30psi without getting the light.
At night pressure dropped to 31 psi...BAM, tire light. Up to 34-35psi on the highway, no luck, didn't disappear.
Owners manual, doesn't appear to show the threshold values nor if they're different front to rear.
Oh well, starting to get used to the tire light since the thresholds have been too high on trucks since the whole tpms mandate began.
Just venting...

[Grit_dog]

Think the new 1500s trip the id10t light and danger warnings (lol) at 31 psi. Filled up up to 35 last night (on the TPMS reading) and lights went out.
This AM, they read 32psi on the tpms readout and no lights came on.

[blt2ski]

My 285's empty if I have more than 33-35 at any temp, the outside of the tread is not contacting the ground. I'm keeping them 30-32. Being as mine is older, I'm not setting a code on my 1500. Even as grit noted, when temp dropped a few times into the upper 50, low 60F I was seeing 27-29 on dash, and Guage.

Marty

[Grit_dog]

mkirsch wrote:
Why you running the tires so low in the first place? I run about 35-37 cold, get long life out of the tires, very even wear, better fuel economy, and great traction in the winter.

Also, no TPMS warning light.

Yeah, I'll bump them up a bit to get rid of the warnings and idiot light, no problem there.
But I'm not running them "so low". At the 33-34 psi I set them at "cold" (on a 90deg afternoon when I rotated them) turned to 31 psi on the ensuing 60 deg mornings. More than enough air for a 285 wide tire on the back of an empty half ton truck.
It's just not enough for the General Motors legal team apparently!

[mkirsch]

Why you running the tires so low in the first place? I run about 35-37 cold, get long life out of the tires, very even wear, better fuel economy, and great traction in the winter.

Also, no TPMS warning light.

[blt2ski]

I'm driving a different frod transit than I normally drive. The light is on. Wondering if it goes on with too much air. Have 65 in the fronts, and normal is supposed to be 50. Rears are at normal 70.
I'm normally at 55 f, 65 rear for my typical loads etc. When I start hauling 3 pallets of antifreeze at 2100 per, I put rears at iirc max is 85 on the funky tiny 235-60-16 or some such size. About same diam as a 235-75-15. Don't haul 3000 per tire rating worth squat either.

Marty

[Grit_dog]

^My last Chevy 1500, 2016 model didn’t trip the TPMS at 32 psi or whatever this one is tripping at. I don’t recall getting a flat, but I know in the winter the rears were under 30psi sometimes with no issue.
Hell, I’m even getting used to the tire light as it’s a problem with most newer trucks. But the extra buttons to push at every startup to clear the “warnings” is really annoying.

[blt2ski]

Sounds like what happened when I got new tires. But drivers side were reversed! Had 50 in front, 35 in the rear perbtpms. When it was 50 rear 35 front.
Then read what it took to fix the issue. PITA to say it lightly. A week later one of my son's and I put a rear helper lift spring, new shocks on the rear. I swapped tires front to rear. All is good now after adjusting the tires.
I'm not running much less than 30 in the new meats, that has not set any codes. Nor has a few times on colder mornings when they dip to 27-28 psi until it warms up

Marty

[ShinerBock]

IdaD wrote:

Same on my Ram. Only problem with it is I get the idiot light all winter because I drop my rear tires to around 60. Suffering a quarter inch idiot light and a warning ding at startup isn't the end of the world, though.

Buy a Bluetooth OBD reader that will pair with your phone. I have OBDLINK MX, but most will work.

Buy the AlfaOBD app on your phone.

Get your 4 digit key code(the one for your key fobs) from the dealer parts/service department. You may have to show proof of ownership.

Use AlfaOBD to set the TPMS to whatever threshold you want and then reset the body control module with the key code. No more light until you reach the threshold you set it at. You can also code in some other things on your truck or any Mopar vehicle as well depending on your make/model/year.

I can PM you my personal phone number if you need help with the process.

[Grit_dog]

noteven wrote:
On my old 2012 Ford 3 fitty I had the tire shop adjust the threshold to 30 psi on the rear. I run 32-35 on the rear when bob tail

I usta have the Ford shops adjust down my F250s. Idk what you'd adjust on a 350 though, since they are just an information system with no low pressure threshold?
That said, I agree with low rear tire pressures running empty.
But about 5 years ago, something changed and dealers can't /won't adjust them anymore.
I know definitively, FCA's diagnostic software removed the ability to adjust. Only means now I'ma ware of is aftermarket programmers/diagnostics like Autel.

[noteven]

On my old 2012 Ford 3 fitty I had the tire shop adjust the threshold to 30 psi on the rear. I run 32-35 on the rear when bob tail

[Grit_dog]

Admin wrote:
Go back to the tire place, they should have reset the tires to the new position.
I had the same reset problem but luckily caught it before driving off.

Admin

Except I was the tire place in this scenario. Much quicker than taking it in for a rotation.
And I don’t care personally if I know which one is where. Only 4 to keep track of.
But I do wonder if they have different thresholds F and R. Probably not on a half ton.
Not interested in the time to make it a science project to find out either.

[Grit_dog]

Groover wrote:
I have a friend who had her tires rotated at the Chevy dealer who also neglected to reprogram the tire locations. A few weeks later the system told her that she had a flat (which she did) but she couldn't find it because it told it to look at the wrong tire. The dealer must have also over-tightened the lug nuts because we destroyed the factory lug wrench getting nuts off. Or maybe the lug wrench was just a piece of garbage. Or both.

It seems that my 2016 F150 knows which tire is where because the display follows the tires when I rotate them. And I know that I haven't reset anything.

Yeah ford and Chrysler are good like that. GMs apparently don’t have the technology yet….

[IdaD]

Groover wrote:
It seems that my 2016 F150 knows which tire is where because the display follows the tires when I rotate them. And I know that I haven't reset anything.

Same on my Ram. Only problem with it is I get the idiot light all winter because I drop my rear tires to around 60. Suffering a quarter inch idiot light and a warning ding at startup isn't the end of the world, though.

[Groover]

I have a friend who had her tires rotated at the Chevy dealer who also neglected to reprogram the tire locations. A few weeks later the system told her that she had a flat (which she did) but she couldn't find it because it told it to look at the wrong tire. The dealer must have also over-tightened the lug nuts because we destroyed the factory lug wrench getting nuts off. Or maybe the lug wrench was just a piece of garbage. Or both.

It seems that my 2016 F150 knows which tire is where because the display follows the tires when I rotate them. And I know that I haven't reset anything.