Mercedes-Benz ML350 Ad Blue signal issue preventing car from starting after fluid addition on Mercedes-Benz ML350

Some Mercedes-Benz ML350 owners report experiencing AdBlue signal issues that prevent the car from starting, even after adding fluid. These problems can stem from common faults within the SCR system or NOx sensor failures, which are critical for reducing harmful emissions. Additionally, a low AdBlue warning indicates that the fluid level is insufficient and requires immediate attention. Owners may find that resetting the AdBlue warning involves diagnosing the issue and using a diagnostic tool to clear the alert, but if standard methods fail, specific steps, such as holding the ignition in position 1 for over 30 seconds post-refill, may be necessary. Persistent warnings after refilling the AdBlue tank suggest a more significant issue that warrants professional evaluation. It is essential for owners to address these concerns promptly to maintain the AdBlue system's functionality and overall vehicle performance.