General Motors LLC (GM) is recalling certain 2020 Cadillac CT6 vehicles equipped with dealer-installed accessory 20″ x 8.50″ wheels (RPO 5JO or SHH). The tire pressure monitoring system (TPMS) sensors use the incorrect wireless radio frequency and cannot illuminate the low pressure warning light when the tire pressure drops below the recommended level. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 138, “Tire Pressure Monitoring Systems.”