TPJLR.18.107 UWB PEPS Keychain Electrical and Mechanical Robustness

The “TPJLR.18.107 UWB PEPS key fob electrical and mechanical integrity” standard, published by Jaguar Land Rover Limited (JLR), guarantees that the key fob meets quality criteria for electrical performance, e.g., no degradation in the ultrawideband (UWB) range after stress, and mechanical integrity, e.g., no cracks in the housing or button malfunctions.

UWB PEPS key fob electrical and mechanical robustness refers to the testing and verification requirements for the durability, reliability and performance of ultra-wideband (UWB) passive entry passive start (PEPS) key fobs in automotive applications, particularly in Jaguar Land Rover (JLR) vehicles.

Jaguar Land Rover (JLR) has integrated ultrawideband (UWB) technology into its passive entry passive operation (PEPS) systems, which are becoming more widely adopted in new models to enhance security against relay attacks. Traditional PEPS systems rely on signal strength typically via LF/UHF or BLE, making them vulnerable to signal amplification by intruders. Ultrawideband, using frequencies in the 3,1–10,6 GHz band, adds precise time-of-flight range (accuracy at the centimeter level) and makes relay attacks virtually impossible due to detectable delays.

Prior to 2018, standard PEPS keys operated via proximity sensing but lacked UWB functionality. After 2018, UWB PEPS keys (fully keyless models) require UWB for full functionality (passive unlocking/starting). A non-UWB key in a UWB-enabled vehicle will only allow remote locking and unlocking, not engine starting.

Therefore, replacement keys for modern JLR models must match the system configuration. This is usually verified by an authorized service technician through diagnostics performed on the body control module or remote function actuator.

In terms of electrical robustness, the focus is on ensuring that the key fob's electronic components (UWB transceiver, microcontroller, battery, antennas) maintain radio frequency performance and safety while withstanding environmental and operational stresses:

• Power transmission and signal integrity tests: Verify the robustness of the ultrawideband (UWB) transmitter (e.g., spectral analysis, occupied bandwidth, channel power, unwanted emissions).
• Interference immunity: The wide bandwidth of ultra-wideband provides high resistance to jamming or noise.
• Flight time distance measurement accuracy: Tested under various conditions to ensure reliable distance measurement.
• Battery life and low-power operation: The remote control must wake up efficiently on LF/BLE triggers and respond over ultrawideband (UWB).
• Functional verification: Emulation of PEPS ECU (engine control unit) communication, including relay attack prevention simulations.

These are compatible with broader automotive radio frequency tests.

In terms of mechanical robustness, it ensures that the physical casing and internal components can withstand daily use and harsh conditions:

• Drop tests: Tests involving drops from various heights onto hard surfaces.
• Vibration and shock: Tests simulating vehicle movement or carrying in a pocket.
• Button durability: Press cycles (lock/unlock/panic).
• Environmental exposure: Temperature cycle (minus 40 degrees to plus 85 degrees), humidity, salt spray/corrosion, dust/water ingress (IP rating).
• Impact and crush resistance: To prevent damage from pockets, bags, or accidental drops.

The TPJLR.18.107 standard pertains to UWB PEPS key fobs. “18” refers to electrical/electronic subsystems (radio frequency/communication or access systems), while “107” covers the unique test for robustness verification. This standard defines pass/fail criteria for ultra-wideband (UWB) key fob suppliers to ensure long-term reliability in vehicles.

Ultrawideband (UWB) is a short-range wireless communication technology that transmits data using very short pulses (on the order of nanoseconds) over a frequency bandwidth typically wider than 500 MHz. This wide spectrum distinguishes it from narrower-band technologies like Bluetooth or Wi-Fi by providing highly accurate distance measurement and location tracking, low power consumption, and resistance to interference.

UWB transmits billions of short radio pulses across a wide frequency range (typically 3,1–10,6 GHz). Devices measure the flight time—the time it takes for the pulses to travel between them—and calculate the distance with centimeter-level accuracy (typically 10⁻³⁰ cm). Techniques such as angle of arrival or time-of-arrival make direction and positioning even more feasible. Its low-power spectral density allows it to coexist with other signals without significant interference.

Ultra-wideband (UWB) plays a crucial role in modern digital car keys, enabling secure, hands-free vehicle access using smartphones or smartwatches. This technology supports passive keyless entry and start. The vehicle automatically unlocks when the driver approaches (without touching the phone) and locks when they walk away.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its customers, providing the advanced testing services they require, and assisting in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services to businesses in accordance with the "TPJLR.18.107 UWB PEPS key fob electrical and mechanical integrity" standard.