Powertrain
generic / SAE
P2AA4
Cold Start EGR B Flow Excessive Detected
During cold start, the ECM detects that EGR channel B delivers more exhaust mass than commanded. Engine smoothness and warm-up calibration may be affected.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / numberA / A4
Possible causes
- EGR valve stuck partially open high
- Actuator overshoots commanded position 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: hard
- DIY: shop recommended
- Estimated cost: 300–1800 €
- Estimated time: 1.5–6 h
- Component: egr valve b
- Component: egr cooler b
- Component: egr diff pressure sensor
- MIL / check engine light
- emissions-relevant
- drive cycle required
- limp mode possible
Sources
References
sae:J2012