Mercedes AdBlue Quality Factor Reset
Supported coding features by StarCOM diagnostic tool https://www.obdtester.com/starcom
What it does
- Resets the learned AdBlue quality factor in the SCR control system
- Allows the ECU to relearn the urea concentration and quality
- Restores proper NOx reduction and SCR operation
When it is required
- After refilling the AdBlue tank
- After replacing AdBlue or SCR components
- When AdBlue quality fault codes are present
- When incorrect or contaminated AdBlue was previously detected
Conditions that must be met
- AdBlue tank filled with correct ISO 22241 fluid
- No leaks in the SCR system
- Ignition ON, engine OFF
- Stable battery voltage
- No active SCR hardware fault codes
What happens during the reset
- ECU clears stored AdBlue quality data
- Default quality value is set
- System begins relearning based on:
- NOx sensor feedback
- AdBlue dosing response
- Exhaust gas analysis
If reset is not performed
- Engine power limitation may remain
- AdBlue or SCR warning messages persist
- Increased emissions
- Vehicle may enter no-start countdown mode
After reset
- Drive vehicle under normal conditions
- Monitor AdBlue and SCR status
- Verify no SCR or AdBlue warnings remain