This one has me scratching my head. The tire pressure listed on the door sticker is 48 PSI because it's an HDDP truck. I run the tires at 42 PSI just because it rides so hard fully inflated. I set all the tires the same by setting the output regulator to 42 PSI and they generally track within 1 PSI, although the left front generally shows 1 pound less when cold. It does vary with temperature, sun access etc. It got cold last weekend and stayed that way for a few days. They all dipped down to 38 pounds except the left front which went to 37 pounds and bought up a low pressure alert. I knew the tire was good ran around town and even ran an errand about 30 miles away. The pressures all rose to 41-42 psi yet the left front low pressure never cleared. The weather warmed a bit, I got the compressor out and pumped the left front tire to 46 psi and took a short drive through the neighborhood. The pressure indication on the left front started at 42 and stayed there the whole time. I have the a dongle to set the TPMS and went around to each with it. No change on the left front and the low pressure alert is still in.The whole time the left front shows increased or decreased pressure tracking the other three tires.