EGR lower than desired
Check the VGT and the EGR valve. Check if the EGR is mechanical restricted. Check for EGR leakage Check the MAF sensor Check the MAP/ boost pressure sensor Check the Boost temperature sensor Check the Exhaust pressure sensor For Eu5 vehicles After repair run the " Checking the EGR system for devalidation of fault codes" . If the performance test could not finish for some reason, use the opportunity to erase NOx control DTC:s For Eu6 vehicles After repair run the workshop test for adaptation of MAF or " Checking the EGR system for devalidation of fault codes".
What you'll see
No driver-visible symptom recorded.
System reaction
Mass flow sensor measurements will be compensated based on default values.
Diagnostic depth
The requested amount of EGR is lower than desired. Test conditions: Mass flow sensor must be adapted and fuel injection must be higher than min limit.
The control of the EGR is not working properly. Possible faults are: EGR valve stuck closed. EGR restricted. EGR leakage. VGT stuck in open position or limited by over speed protection. MAF defective MAP/ Boost pressure sensor defective Boost temperature sensor defective Exhaust pressure sensor defective