Powertrain
generic / SAE
P04D8
Excessive Time To Enter Closed Loop EGR Control
After cold start the ECU operates EGR open-loop until preconditions (cooler temperature, sensor warm-up, engine load) are met, then transitions into closed-loop control. The transition is taking too long - typically due to a slow EGR temperature sensor, a stuck EGR valve still warming up, or a long-trip drive cycle that does not meet load conditions.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number4 / D8
Possible causes
- EGR temperature sensor responds slowly high
- Short-trip operation - load conditions not met 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: 200–800 €
- Estimated time: 1–3 h
- Component: egr valve a
- Component: egr temperature sensor a
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012