Record codes and inducement state
Capture every engine and aftertreatment code, freeze-frame data, remaining distance or starts, reagent level and quality values, SCR efficiency and NOx readings. Do not erase evidence before understanding why inducement was requested.
Some platforms require a specific repair confirmation, drive cycle or service procedure after the physical fault is corrected. A generic code clear may not release the countdown.
Verify fluid, pressure and dosing
Confirm the correct fluid specification and check contamination, crystallization, freezing damage and tank condition. Compare commanded and measured pressure while inspecting pump current, supply, return and leakage.
Inspect the dosing injector and mixer for restriction or deposits. A quantity or spray-pattern test should follow manufacturer procedure and safe chemical handling.
Evaluate sensors and catalyst conditions
Compare upstream and downstream NOx values for plausibility with exhaust temperature, load and dosing state. Heater, communication and ageing faults can influence efficiency diagnosis.
SCR conversion cannot be judged correctly when exhaust temperature is too low, dosing is inhibited or upstream engine faults create abnormal emissions. Diagnose EGR, boost, combustion and DPF conditions where related.
Finish with the correct reset and legal outcome
After repair, perform the documented priming, learned-value or inducement-reset routine and complete the required confirmation cycle. Preserve the before-and-after data.
Required road-vehicle emissions systems must remain operational. For a legally permitted declared application, use the controlled AdBlue/SCR workflow and supply all diagnostic context.