So i bought new tires yesterday for my 2009 GMC Sierra . I went up one size to 275/75 18 i think it was. Anyway after they got done and brought it out to me , i noticed that the tire pressure looked low. he says that he cant put the right amount of pressure in them because the TPM system will notice . Everything i read in the manual talked about low air pressure, nothing about high. The truck drove awful and i have to put the right amount of air in them. Is this going to affect anything or will the TPM even notice?