A keyless vehicle entry and start system for motor vehicles includes an input device such as a keypad and a backup electrical power supply to unlock the door latch in the event the primary power supply fails, thereby eliminating the need for a lock cylinder. The door latch system is configured to supply electrical power from the primary electrical power supply to unlock the latch upon receiving a signal from a mobile phone, and to supply electrical power from the backup electrical power supply to unlock the latch if an authorized code is input via the keypad. The system is configured to communicate with a portable wireless device such as a smartphone utilizing various frequency bands. The system permits entry and operation of a vehicle utilizing only a smartphone.