Tire pressure sensor settings

[ReddJackson]

Didn’t find a answer via search…
How do the TP sensors determine what pressure should be…is it automatically controlled or does the optimum pressure have to be adjusted manually?
Thanks

 

[MADDOG]

The TP sensors I am familiar with are simply there to measure the PSI. To reach the optimum PSI you have to add or remove air manually.

 

[ReddJackson]

well yeah, that I know…my sensor came up with a alert saying my rear tires were low and to inflate to 80psi… so do the sensors automatically know what the pressure should be according to the tires or do the high/low pressure sensor limits have to be manually adjusted entered to the recommended pressure on the tires?
My bad, should have explained better.

 

[MADDOG]

No, they do not know anything automatically with respects to what the PSI should be given for any given tire type, size or manufacturer.

In any event, I would not inflate to 80 psi unless I was heavily loaded and towing something. I ran my Cummins with 35 x 12.50/R17 Nitto Terra Grapplers at around 38 psi cold after doing a chalk test at various pressures to avoid under or over inflating the tires. When I towed heavy, I would increase the psi to just under the max pressure recommended by Nitto for those tires.

That 80 psi rating is a pre-programmed setting in the BCM which you can't touch without the tech scan tool available at a dealer's shop.

Finding the right PSI for your tires is a totally manual process. The sensor's only value is keeping tabs on the current tire PSI.

 

[ReddJackson]

Thanks, exactly what I needed to know

 

[62Blazer]

It's already been explained, but....
The computer has preset required pressures in it depending on what is required from the factory. Many different models of vehicles may use the exact same sensor that is just reporting a number to the computer. The computer then determines if that number matches the range that is programmed from the factory for that particular setup. For exampe on a heavy duty truck it may want 80 psi, but a car may use the exact same sensor but only need 35 psi.
If 80 psi is the recommend pressure, there is a range of pressure the tire can be at before the light on the dash comes on. For example it can normally drop down around 10% or so before it triggers the alarm, which would be around 72 psi. This is because the pressure fluctuates with temperature. If they had to stay at exactly 80 psi the light would always be coming on.
As mentioned, the 80 psi is what is recommended if running at full load/weight on the truck. Not what is needed under no load for best handling, ride, and traction. A lot of people run lower pressures for that reason. There are multiple devices that can repgrogram the pressure thresholds. The recommend pressure at full load is also only applicable for the stock rating of the tire. If the stock tires have a max rating of 80 psi you can run 80 psi. But for example if you install aftermarket tires that only have a rated max psi of 65 psi......you should not run 80 psi in them.

 

[RamDiver]

There are several apps capable of adjusting the tire pressure threshold settings on our trucks.

AlfaOBD has that feature and many more tweaks. The adjustments for my truck are 10-80 PSI.





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[ReddJackson]

Thanks for all the support/info…seriously much appreciated

 

[chaser841]

There are several apps capable of adjusting the tire pressure threshold settings on our trucks.

AlfaOBD has that feature and many more tweaks. The adjustments for my truck are 10-80 PSI.


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So I have been looking at this cause I need to change this on my 2014. Looking at the AlfaOBD software and I think OBDLink MX+. Question is after you program the changes, can you unhook the MX+ or does that thing need to stay plugged in?

 

[aszumilo]

So I have been looking at this cause I need to change this on my 2014. Looking at the AlfaOBD software and I think OBDLink MX+. Question is after you program the changes, can you unhook the MX+ or does that thing need to stay plugged in?

Once you program it, you can remove the MX+

 

[RamDiver]

So I have been looking at this cause I need to change this on my 2014. Looking at the AlfaOBD software and I think OBDLink MX+. Question is after you program the changes, can you unhook the MX+ or does that thing need to stay plugged in?

One of the great features of AlfaOBD, you write the changes to the BCM or other modules and then remove your interface equipment.

With the 2018+ vehicles where you require a security bypass harness, if you buy the ideal harness, install it and forget it.

Coil it up and stuff it behind the dash and it's out of site but ready to quickly reconnect to the OBD2 connector for your next tweaking session.

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