OBD-II code · Powertrain (generic, extended)
P20A0 Reductant Purge Control Valve A Circuit/Open
The reductant purge control valve A drive circuit is open — used to evacuate DEF lines back to the tank when the engine is shut down to prevent freezing damage.
Is it safe to drive with P20A0?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySolenoid winding open
- 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
- Best left to a mechanic
- Typical labour
- 0.7–2.5 h
- Emissions test
- Likely to fail
- Parts involved
- Reductant Purge Valve
Related codes
- P209DReductant Injection Air Pressure Sensor B Circuit High
- P209EReductant Injection Air Pressure Sensor A/B Correlation
- P209FReductant Tank Heater Control Circuit Performance
- P20A1Reductant Purge Control Valve A Performance
- P20A2Reductant Purge Control Valve A Circuit Low
- P20A3Reductant Purge Control Valve A Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.