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.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
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
Common causes
Ordered by how often each turns out to be the cause.
- Long-term drift upwardCommon
Parts involved
- Fuel Pressure Regulator
P229D 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.