P2BAE
NOx Exceedence - EGR System
NOx emissions are above the legal threshold and the ECU isolates the cause to the EGR system. EGR flow is too low or absent under operating conditions where NOx reduction is required.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Common causes
Ordered by how often each turns out to be the cause.
- EGR valve stuck closedCommon
- Carbon clogged EGR passagesCommon
Parts involved
- EGR Valve
- EGR Cooler
- EGR Diff Pressure Sensor
P2BAE is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.