P2AA6
EGR Cooler Bypass Control Circuit Driver Current/Temperature Too High Bank 2
The output driver for the EGR cooler bypass actuator on bank 2 reports current or junction temperature above its protection threshold. Stalled actuator or short to ground.
- 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.
- Bypass actuator mechanically jammedCommon
- Control wire shorted to groundPossible
Parts involved
- EGR Cooler Bypass Actuator B2
- ECM
P2AA6 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.