Full explanation
How it works: the tractor ECU serializes each replacement part (NOx sensor, DPF, injectors, EGR valve, TCU module) with a cryptographic handshake that's only validated via the dealer tool (John Deere Service ADVISOR €3 500/yr subscription + €500–1500 per farm call). Same pattern: CNH EST for New Holland/Case, AGCO EDT for Fendt/Massey Ferguson, Claas CDS. Practical impact: a NOx sensor for a JD 6M costs UAH 2 100 via agra-port; official replacement with activation at the dealer UAH 40 000+ (part, call-out, 2 h labour, VAT). Workarounds: (a) right-to-repair movement in the EU (EU Reg 2023/1542) + American AG Right-to-Repair (Nebraska, Colorado) is gradually forcing OEMs to open diagnostic interfaces — JD began selling a partial Customer Service ADVISOR at €650/yr from 2024; (b) ECU-clone boxes from FJDynamics and third-party Russian-Chinese suppliers exist but are sanction-risky and may disable telematics. Basis for the OEM-vs-aftermarket calculator: dealer-lock flag multiplies aftermarket savings by 0.6–0.7 via invisible service fees. Source: machinery-kb.ts `dealer_lock_flag` field + oem-aftermarket-cross-reference calculator.