Customer lost all keys. Vehicle immobilised and will not start after an all keys lost procedure.

Vehicle presented as an all keys lost job on a bladed ignition Hiace using Toyota 8A transponder. All keys lost programming was carried out with locksmith tooling (Autel and Xhorse Toyota 8A AKL adaptor) and the immobiliser light on the dash would go out with the programmed key inserted, with immobiliser live data appearing correct and recognising the key. Despite this, the engine would not start and the ECM consistently logged an immobiliser fault. The root cause was poor connections and corrosion affecting immobiliser and ECU communication, including an immobiliser module that had been relocated and left exposed under the dash, plus corrosion at connectors near the cabin fuse box. Cleaning and treating the affected connectors restored communication, the fuel cut status returned to normal, and the engine started.