OBD-II code · Powertrain (generic, extended)

P2AA5 EGR Cooler Bypass Control Circuit Driver Current/Temperature Too High Bank 1

The output driver for the EGR cooler bypass actuator on bank 1 reports current or junction temperature above its protection threshold. Stalled actuator or short to ground.

Is it safe to drive with P2AA5?

The car may go into limp mode (reduced power). Get it diagnosed before a long trip.

Common causes

  • Most likelyBypass actuator mechanically jammed
  • PossibleControl wire shorted to ground

Symptoms

  • Check engine light on
  • Pinging or knocking under load
  • Power loss and hesitation
  • Possible rough idle
  • Failed emissions inspection (NOx)

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
2–6 h
Emissions test
Likely to fail
Parts involved
Egr Cooler Bypass Actuator B1, Ecm

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.