Powertrain
generic / SAE
P04D9
Closed Loop EGR Control At Limit Flow Too Low
With EGR running in closed loop the controller has driven the actuator to its maximum opening but cannot reach the required EGR flow. The valve, cooler, or pipework is restricted enough that even full open does not deliver the modelled rate.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number4 / D9
Possible causes
- EGR cooler clogged with soot high
- Valve effective opening reduced by carbon medium
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Inspection / repair
- Difficulty: medium
- DIY: shop recommended
- Estimated cost: 300–1500 €
- Estimated time: 1.5–5 h
- Component: egr valve a
- Component: egr cooler a
- Component: egr pipework
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012