Tamper security systems and methods for vehicles

1. A passive entry/passive start (PEPS) system comprising:

a communication gateway in a vehicle configured to transmit a ping signal based on at least one of a predetermined period and a predetermined transmission power level;

at least one sensor configured to receive the ping signal and measure a physical characteristic of the ping signal;

a central module in the vehicle configured to receive the measured physical characteristic of the ping signal through a vehicle interface, determine a lower threshold and an upper threshold associated with the at least one sensor, and compare the measured physical characteristic of the ping signal to the lower threshold and the upper threshold; and

in response to determining that at least one of the measured physical characteristic is less than the lower threshold and the measured physical characteristic is greater than the upper threshold, the central module is further configured to notify a portable device that the at least one sensor has been tampered with.

2. The PEPS system of claim 1 , wherein the measured physical characteristic of the ping signal includes at least one of a received signal strength indication (RSSI), a time of flight, a time difference of arrival, and a time of arrival.

3. The PEPS system of claim 2 , wherein the ping signal is transmitted using radio frequency signals including at least one of a low frequency signal, a high frequency signal, and an ultra-high frequency signal.

4. The PEPS system of claim 3 , wherein the ultra-high frequency signal includes a Bluetooth Low Energy (BLE) signal.

5. The PEPS system of claim 2 , further configured to receive a location of the portable device from a localization module and to perform a vehicle function including at least one of unlocking a door of the vehicle, unlocking a trunk of the vehicle, and allowing the vehicle to be started based on the location of the portable device.

6. The PEPS system of claim 2 , wherein the central module determines the lower threshold and the upper threshold based on a probability curve associated with the at least one sensor, wherein the probability curve is determined based on an expected RSSI of the ping signal by the at least one sensor.

7. The PEPS system of claim 6 , wherein the expected RSSI of the ping signal increases in response to at least one of a distance between the at least one sensor and the communication gateway decreases, and the predetermined transmission power level increases.

8. The PEPS system of claim 6 , wherein the expected RSSI of the ping signal decreases in response to at least one of a distance between the at least one sensor and the communication gateway increases, and the predetermined transmission power level decreases.

9. The PEPS system of claim 1 , wherein notifying the portable device that the at least one sensor has been tampered with includes the central module transmitting an alert to a graphical interface on the portable device.

10. The PEPS system of claim 1 , wherein the ping signal is transmitted using the vehicle interface, the vehicle interface is a wired connection between the communication gateway and the at least one sensor.

11. A method comprising:

transmitting a ping signal with a communication gateway in a vehicle based on at least one of a predetermined period and a predetermined transmission power level;

receiving the ping signal with at least one sensor and measuring a physical characteristic of the ping signal;

receiving the measured physical characteristic of the ping signal with a central module in the vehicle through a vehicle interface;

determining, with the central module, a lower threshold and an upper threshold associated with the at least one sensor;

comparing, with the central module, the measured physical characteristic of the ping signal to the lower threshold and the upper threshold; and

notifying a portable device that the at least one sensor has been tampered with in response to determining, with the central module, that at least one of the measured physical characteristic is less than the lower threshold and the measured physical characteristic is greater than the upper threshold.

12. The method of claim 11 , wherein measuring the physical characteristic of the ping signal includes at least one of a received signal strength indication (RSSI), a time of flight, a time difference of arrival, and a time of arrival.

13. The method of claim 12 , wherein transmitting the ping signal using radio frequency signals includes at least one of a low frequency signal, a high frequency signal, and an ultra-high frequency signal.

14. The method of claim 13 , wherein the ultra-high frequency signal includes a Bluetooth Low Energy (BLE) signal.

15. The method of claim 12 , further comprising:

receiving a location of the portable device from a localization module; and

performing a vehicle function including at least one of unlocking a door of the vehicle, unlocking a trunk of the vehicle, and allowing the vehicle to be started based on the location of the portable device.

16. The method of claim 12 , wherein determining the lower threshold and the upper threshold is based on a probability curve associated with the at least one sensor, wherein determining the probability curve is based on an expected RSSI of the ping signal by the at least one sensor.

17. The method of claim 16 , wherein the expected RSSI of the ping signal increases in response to at least one of a distance between the at least one sensor and the communication gateway decreases, and the predetermined transmission power level increases.

18. The method of claim 16 , wherein the expected RSSI of the ping signal decreases in response to at least one of a distance between the at least one sensor and the communication gateway increases, and the predetermined transmission power level decreases.

19. The method of claim 11 , wherein notifying the portable device that the at least one sensor has been tampered with includes the central module transmitting an alert to a graphical interface on the portable device.

20. The method of claim 11 , wherein transmitting the ping signal using the vehicle interface, the vehicle interface is a wired connection between the communication gateway and the at least one sensor.