2.2 MZR-CD Diesel SCR AdBlue Heater and Level Sensor Failure
ModerateExhaust & EmissionsFacelift 2.2 MZR-CD diesel models feature an AdBlue Selective Catalytic Reduction (SCR) system with a reservoir tank located under the boot floor. The tank houses an integrated heating element, level sensor, and dosing pump. Over time, crystalline AdBlue deposits corrode the internal level sensor circuitry or the heating element fails. The instrument cluster displays an 'SCR Malfunction' warning accompanied by a countdown of miles remaining before engine restart is permanently prevented. Because the sensor and heater are built directly into the plastic tank assembly, dealerships traditionally replace the complete tank unit at significant expense.
SCR System Malfunction warning message displayed on the dashboard, Miles-to-no-restart countdown warning displayed on instrument cluster, Check engine light illuminated with SCR reductant system trouble codes
- Confirm that the dashboard displays no SCR or AdBlue warning lights or restart countdowns
- Inspect around the boot floor AdBlue filler neck for heavy white crusty crystalline leakage