What Is JLR Secure Diagnostics?

Secure Diagnostics (Quick Overview)

  • Introduced by Jaguar Land Rover in August 2025 on 26MY Defender and Discovery
  • Required by UNECE UN R155 (Cybersecurity) and UN R156 (Software Updates)
  • Locks diagnostic, coding, and programming access at the vehicle network level
  • Vehicle must be unlocked by an authenticated dealer-level diagnostic system
  • This is not a software toggle or setting — it’s built into the vehicle architecture

Why Many Tools No Longer Work

  • Secure Diagnostics vehicles cannot be programmed by generic diagnostic tools
  • Read-only access may still work, but writing and coding are blocked
  • Authentication is required to unlock modules for programming

OEM Activations Compatibility

  • Uses authenticated dealer software compatible with Secure Diagnostics
  • Can unlock secure sessions and perform supported programming
  • No bypasses, exploits, or unsupported methods
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