OBD-II code · Powertrain (generic, extended)

P229D Fuel Pressure Regulator B Exceeded Learning Limits - Too High

The adaptive learning offset for fuel pressure regulator B has reached the upper limit. Long-term drift upward indicates progressive wear of the regulator or a return path that is becoming restricted.

Is it safe to drive with P229D?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelyLong-term drift upward

Symptoms

  • Check engine light on
  • Hard start, no start, or stalling under load
  • Power loss especially at high load or rpm
  • Possible long cranking time

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
1.5–6 h
Emissions test
Likely to fail
Parts involved
Fuel Pressure Regulator

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