Low tire pressure warning
02-23-2019, 08:30 AM
#1
Senior Member
Thread Starter
Low tire pressure warning
I have a '19 F150 XL 4x4 with 5.0 and 10sp. When not towing or hauling I run the tire pressure at 42/28 F/R cold. I was getting away with it for a while but now the low tire warning is on and won't go off. It seems to be O.K. with the fronts but shows the rears in orange on the individual pressure readout. Is there a way to reset the normal pressures the computer is looking for?
02-23-2019, 08:35 AM
#2
I have a '19 F150 XL 4x4 with 5.0 and 10sp. When not towing or hauling I run the tire pressure at 42/28 F/R cold. I was getting away with it for a while but now the low tire warning is on and won't go off. It seems to be O.K. with the fronts but shows the rears in orange on the individual pressure readout. Is there a way to reset the normal pressures the computer is looking for?
02-23-2019, 08:44 AM
#3
Senior Member
Thread Starter
What is the proper PSI? My F150 with driver has 60% of the weight on the front tires with the same size tires on both ends. Do you know anything about contact patch size?
02-23-2019, 08:47 AM
#4
look on the door jam sticker...
The TPMS uses 4 valve stem mounted sensors to monitor tire pressure. These sensors wirelessly transmit tire pressure data to the RTM. The RTM is a radio signal receiver which collects the tire pressure data and sends the information to the BCM along a LIN. All TPMS functions are controlled by the BCM. The BCM compares the tire pressure data sent by the RTM with a programmed tire pressure. This programmed pressure is specified on the VC label and cannot be changed. If the actual tire pressure is less than the programmed tire pressure, the BCM sends a low tire pressure message to the IPC along the HS-CAN3. The IPC responds by illuminating the TPMS warning indicator and displaying a low tire pressure message in the message center
Last edited by djfllmn; 02-23-2019 at 08:59 AM.
02-23-2019, 08:56 AM
#5
Senior Member
Thread Starter
Tire pressure varies considerably depending on atmospheric pressure, ambient temperature, pavement temperature, load and speed the tire is operating at. The BCM has to be programmed to accept a range of tire pressures. I suspect that this can also be reprogrammed like just about everything else.
02-23-2019, 08:58 AM
#6
Tire pressure varies considerably depending on atmospheric pressure, ambient temperature, pavement temperature, load and speed the tire is operating at. The BCM has to be programmed to accept a range of tire pressures. I suspect that this can also be reprogrammed like just about everything else.
Last edited by djfllmn; 02-23-2019 at 09:01 AM.
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idrive (02-23-2019)
02-23-2019, 09:48 AM
#7
Return tire pressure to the recommended 35 psi. You were right about tire pressure fluctuations based on different variables, especially temperature. Pressure increases and decreases based on temperature and running 42psi cold may rise to above the maximum pressure the tire can withstand on a hot day. And the Ford Explorer/Firestone debacle reminds us all of what happens when you drive with under inflated tires. The Explorer blowouts is why we have mandatory TPMS.
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chimmike (02-23-2019)
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02-23-2019, 09:49 AM
#8
What’s more, the tire’s contact patch—where the rubber meets the road—will not be its correct shape. This puts more wear on the tire’s shoulders, those rounded parts of the tire between the sidewall and the tread. The tire will also likely have less grip if under inflated,
02-23-2019, 10:10 AM
#10
Senior Member
Drop your front to 40, and the rear up to 34. I check my tires with a tread depth guage and was able to go 20,000 miles before the first rotation.