TPMS and Tire Pressures.
 

Situation: 2011 CTS with 17" rims and the OEM Michelin tires. HMV Piots (I believe). Tire pressure calls for 36. Had tire pressures checked, tires filled cold to 34. TPMS reads 31 left front /30 right front/31 Driver rear and 30 passenger rear. Ambient temps starting at 0900hrs is 90 degrees (F). Even when driving the air pressures do not exceede these pressures. Car has apprx 1400 miles on the clock. Wondering if anyone has had similar TPMS problems. I will recheck tomorrow and report back. Possible causes, faulty TPMS tire sensors (Cannot believe all four), faulty reception by the TPMS module in car (Calibration needed?) or slow air leaks on all four wheels. (This would be hard to believe BUT the car has been sitting.) Also getting steering wheel vibration at 55 MPH. (Left to right as opposed to up and down) My guess they should be rebalanced first. Thanks for any assistance or worthwhile guesses. SWAGs are welcomed too.

I am a mechanic by profession and interested in automotive field.Your tires is of good condition i guess and teh pressure you noted is also fits.Actually your car is of old version so vibrating and other minor issues are counted.So don,t your car is fit.