I had a nail in a rear tire that caused it to loose pressure, got it to a tire place and they fixed the tire. After, at startup and if I'm stopped for a while, my PSM Failure light and message come on. I checked the TPS and it has both fronts at 25PSI and left rear 33PSI, right rear (The one that was fixed) at 30 PSI. Would this cause the PSM light to come on?
Anyway I increased the fronts to 30 PSI TPS indication says 27 fronts. Increased the rears to 37 PSI, TPS indication reads 37. Still have the PSM indication.............
Yes, there can be issues with too low a tire pressure front vs rear as the PSM is claibrated within certain tolerances of front tire diameter vs the rear. The rear wheel/tire are a wider cross diameter than the front, and if this front to rear ratio gets too far out it will trick the car into thinking one of the wheels is slipping based on the speed readings of each axle.
The problem I see is your front tire pressures seem way too low. You should be at least 32-33 psi on all of them cold. Look for the recommended cold pressure ratings on the sticker in the drivers door jamb to be sure for your car, but your front tires seem way too low based on your post. 37 on the rear seems too high as well if cold. They will typically start cold at 32-33 and go up to 35 or so when driven and hot. I think you may just have a wrong combo of too high pressure in the back and too low up front and this is throwing the rolling diameter ratio all out of whack and tripping the PSM
My owner's manual and decal in the door jamb indicate that for 19" wheels (which are what I have), tire pressure should be 32 psi for the fronts and 36 psi for the rears. IIRC, the manual also indicates that for 17" and 18" wheels, the tire pressure for the fronts should be 29 psi and 36 psi for the rears. Consequently, depending upon what size wheels the OP has, his front tire pressure should be either 29 psi or 32 psi. His rears should be 36 psi irrespective of whether they are 17", 18", or 19".
Thanks for the inputs. My wheels are stock 18". The door label says 30lb fronts and 37lb rears. The tires have been inflated to these pressures and checked with two different pressure gauges. However the TPS indication is reading 27 Fronts 37 Rears...... Maybe I need some new transmitters.
I don't think the sensors are particularly accurate. My aftermarket versions all read a couple pounds low, and I consider the TPMS to mainly be there to alert me to an issue. In any case, I don't think that has anything to do with your PSM warning. Presumably there is some kind of wheel rotation sensor for PSM - is it possible the sensor/wire/connector got bumped and damaged during the repair?
Its been my experience that the TPMS read outs tend to be a couple of psi lower than what my Longacre gauges read.
Thanks and sorry for the inaccuracy in my initial reply. I was thinking 20's which run different pressure values
