Fault Information

Fault Code Description
Monitoring of NOx efficiency (efficiency range 2). The fault is detected if the average nitrogen oxide efficiency of the SCR system falls below an operating point-dependent, lower limit value.

Fault Code Conditions
General Conditions	Monitoring starts once a new, valid nitrogen oxide efficiency has been calculated. Monitoring is running continuously. Control unit voltage: 9.5 V to 16 V.
Terminal Condition
Driving Conditions

Fault Time Condition
The fault is entered if it has been detected more than the following number of times (fault debouncing counter): 4

Service Plan
1. Check filling level of AdBlue, top up AdBlue. 2. Check that metering valve and the mixer are correctly installed and check for contamination. Clean metering valve with water. Perform metering quantity test. 3. Check for the quality of the dosed out AdBlue. 4. Check with SCR catalytic converter diagnosis system.

Fault Impact
None

Warnings
Warning Lights	None
Control Center Messages

Service Notes
- Check the function of the metering valve and clean with water, if necessary. - nitrogen oxide sensor upstream or downstream of SCR catalytic converter is implausible (note is a corresponding fault code entry), renew sensors. - SCR catalytic converter faulty, perform system test with SCR catalytic converter. Carry out the following service functions depending on which components have been renewed: - AdBlue: SCR system adjustments and adaptations, AdBlue (long-term adaptation factor) - Nitrogen oxide sensors: SCR system adjustments and adaptations, SCR exhaust sensor system - Diesel particulate filter: Diesel particulate filter: register exchange. - SCR catalytic converter: SCR catalytic converter: register exchange. - Metering module: SCR system adjustments and adaptations, SCR metering module - SCR tank system: SCR system adjustments and adaptations, SCR tank system The fault cannot be deleted until the DDE has detected a functioning SCR system. For this purpose, correct faults and complete a conditioning run until the Check Control message goes out. The fault memory can then be deleted.

Service Notes

- Check the function of the metering valve and clean with water, if necessary.
- nitrogen oxide sensor upstream or downstream of SCR catalytic converter is implausible (note is a corresponding fault code entry), renew sensors.
- SCR catalytic converter faulty, perform system test with SCR catalytic converter.
Carry out the following service functions depending on which components have been renewed:
- AdBlue: SCR system adjustments and adaptations, AdBlue (long-term adaptation factor)
- Nitrogen oxide sensors: SCR system adjustments and adaptations, SCR exhaust sensor system
- Diesel particulate filter: Diesel particulate filter: register exchange.
- SCR catalytic converter: SCR catalytic converter: register exchange.
- Metering module: SCR system adjustments and adaptations, SCR metering module
- SCR tank system: SCR system adjustments and adaptations, SCR tank system
The fault cannot be deleted until the DDE has detected a functioning SCR system. For this purpose, correct faults and complete a conditioning run until the Check Control message goes out. The fault memory can then be deleted.