Under the steering wheel, there is a button you need to press to re"initialize" the wheel pressure. The LS430 is not a direct Tire Pressure Monitoring (TPM) system, it uses the ABS system to detect if there is "low pressure" by measuring the spinning difference between tires. So, because of this, if somehow it's detecting that the tire pressures of one (or more) are off, then it trips the TPM. Make sure all your tire pressures are at 32 psi, then reinitialize, and that will be the new baseline that the computer will use.