P009B
Fuel Pressure Relief Control Circuit/Open
Open circuit at fuel pressure relief solenoid (used to bleed off rail pressure during certain operating modes).
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
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.
- Wiring breakCommon
- Pin pushed back out of connector bodyLess likely
- Cracked solder joint inside the module or sensorLess likely
Parts involved
- Pressure Relief Solenoid
- Solenoid Wiring
P009B 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.