Theft Protection Solution

ST35 Tamper-Resistant BLE Immobilizer Solution

  • INTRO

    Vehicle theft, tracker removal, power interruption, and unauthorized use remain persistent security challenges for fleet operators, vehicle finance providers, rental and lease businesses, and recovery service providers.

    ST35 is a Tamper-Resistant BLE Immobilizer Solution that pairs a compatible BLE-enabled ST SUNLAB tracking device with a relay unit installed separately in the engine compartment. Through encrypted BLE communication, the tracking device remotely controls the vehicle's ignition or starter circuit without any additional immobilizer signal wiring.

    Its latching relay holds the last ON/OFF state without continuous coil power, while anti-tamper protection automatically immobilizes the vehicle if the main tracker is removed or its presence signal is no longer detected.

    ST35 is more than a remote-controlled BLE relay. It is designed to address these security challenges.

  • CHALLENGE

    Conventional immobilizer systems often connect the tracking device and the relay with direct wiring. If someone finds that wiring or the tracker, they can disconnect it or bypass the immobilizer circuit. This wiring also adds installation complexity.

    Standard relays often need continuous coil power to hold their state. This makes resistance to power interruption and electrical tampering just as important.

    An effective vehicle security system needs to do the following:

    • Maintain the immobilizer state during power interruption
    • Protect the vehicle even if the main tracker is removed or its presence signal is no longer detected
    • Control vehicle ignition without additional signal wiring
    • Reduce the risk of immobilizer detection, bypass, and tampering
    • Support a wide range of vehicle electrical systems and engine compartment environments

  • SOLUTION

    • Latching Relay Immobilizer Control

      Holds the ignition or starter circuit in its last commanded state, even during a brief power interruption.

    • Automatic Anti-Tamper Protection

      Activates the immobilizer automatically if the main tracker is removed or its presence signal is lost.

    • Hidden Wireless Immobilizer Architecture

      Tracking and immobilizer components are installed separately and communicate over encrypted BLE, making the system harder to find and bypass.

    • Voltage Range and Environment Protection

      The ST35 supports an 8 to 40V input range and IP67 protection, with an operating range of -30°C to +85°C (-22°F to +185°F).
      This allows reliable operation in harsh installation environments like the engine compartment, across passenger and light commercial vehicles.

    • BLE 5.3 Communication and FOTA Support

      Encrypted BLE 5.3 communication with remote firmware updates through a compatible tracking device.

    • ST35 flow chart

  • BENEFITS

    • Reduced Vehicle Loss and Recovery Risk

      Cutting power or removing the tracker does not simply reset the immobilizer protection.
      The ST35 helps maintain vehicle protection in these tampering scenarios, supporting vehicle finance companies and recovery service providers in reducing asset and recovery risk.

    • More Value from Existing Tracker Deployments

      Operators can add the ST35 to a compatible ST SUNLAB tracker already in the field, without replacing the existing tracking hardware.
      This extends existing tracking deployments with immobilizer functionality and creates an additional security upgrade opportunity.

    • Lower Operating Costs Through Installation Standardization

      The ST35 connects wirelessly over BLE and supports a voltage range, reducing the need for separate 12V and 24V variants.
      A single model can therefore simplify installation planning, SKU management, and inventory across mixed vehicle fleets.

    • Reduced Relay Stress and Maintenance Burden

      The latching relay design reduces continuous power consumption and heat generation.
      This can help reduce maintenance burden and improve long-term operational reliability.

    • Harder to Detect or Bypass

      The tracker and the immobilizer relay are installed in different locations in the vehicle, making the complete security system harder to identify and disable.
      This provides an additional layer of protection against unauthorized vehicle use for rental, lease, finance, and fleet operations.

  • APPLICATION

    Vehicle Recovery & Anti-Theft | BHPH & Vehicle Finance | Rental & Lease | Fleet Management | Commercial Vehicle

  • FEATURED PRODUCT