Run System checks 1–3 under EEC > SCR1 > Checks in SDP3 and follow the instructions in the test.See Workshop Manual 03-25, Exhaust gas aftertreatment Euro 4, Euro 5 and EEV, Checking - Troubleshooting for more information about troubleshooting the SCR system.If this does not help:Check whether the vehicle can build up enough pressure in the pneumatic system.Check whether the injection nozzle or pipe between the reductant doser and injection nozzle is blocked. If this is the case, clean with hot water. If the cleaning is successful, there are no faults on these components. Blow into them and run System checks 1–3 under EEC > SCR1 > Checks in SDP3 to verify. If cleaning is not successful, renew the injection nozzle.Check whether the compressed air line between the main unit and reductant doser is blocked or kinked.Clean the reductant doser's air and reductant circuit. Use SDP3 to activate it when cleaning the reductant circuit.Renew the reductant doser.Proceed as follows to verify that the fault has been rectified:There should not be any other active fault codes in the SCR system.The SCR system must be started to verify that the fault has been rectified. Start the SCR system by doing one of the following:Carry out the test Devalidating fault codes for NOx control, which can be found under User functions > Checks in SDP3. Run Dosage test with air and reductant under User functions in SDP3, up to testing the nozzle spray pattern.Run the vehicle so that the system starts. This happens when the temperature goes above 200°C in the silencer. Use System check of the SCR system under User functions in SDP3 to monitor the measurements.If the fault has been rectified, the fault code becomes inactive. Clear the fault code.You can go into fault code monitoring and look at the fault code. There you can see whether the conditions under which the control unit verifies that the fault is rectified have been met. When the conditions have been met and the test is carried out, the fault code status is displayed during the test. If the fault code is pending, the control unit has detected a fault. If the fault has been rectified, the fault code becomes inactive and can be cleared.Switch the 15 voltage off and on three times in succession at 10 second intervals to extinguish the warning lamp.

Diagnostic depth