OBD-II code · Powertrain (generic, extended)
P24DB Reductant Purge Control Valve B Circuit Open
The secondary reductant purge valve B - which clears AdBlue from injector and lines at shutdown to prevent crystallisation - has an open control circuit.
Is it safe to drive with P24DB?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen in valve or wiring
- Less likelyPin pushed back out of connector body
- Less likelyCracked solder joint inside the module or sensor
Symptoms
- Check engine light or NOx warning on
- AdBlue/DEF level or quality warning
- Possible no-start countdown after ignore period
- Failed emissions inspection (NOx)
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.6–2 h
- Emissions test
- Likely to fail
- Parts involved
- Reductant Purge Valve B
Related codes
- P24D8EVAP System Pressure Sensor or Switch B Circuit High
- P24D9EVAP System Pressure Sensor or Switch B Circuit Intermittent
- P24DAParticulate Matter Sensor Exhaust Sample Error Bank 1
- P24DCReductant Purge Control Valve B Performance
- P24DDReductant Purge Control Valve B Circuit Low
- P24DEReductant Purge Control Valve B Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.