OBD-II code · Powertrain (generic, extended)
P20A3 Reductant Purge Control Valve A Circuit High
Reductant purge control valve A drive line stuck high — short to B+. The evaporative system captures fuel vapor from the tank and purges it into intake; leaks or stuck purge valves leak hydrocarbons and cause emissions failures.
Is it safe to drive with P20A3?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyShort to B+
- Less likelyConnector pins corroded - high contact resistance
- Less likelySupply wire pinched against B+ source
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
- P20A0Reductant Purge Control Valve A Circuit/Open
- P24DEReductant Purge Control Valve B Circuit High
- P20A1Reductant Purge Control Valve A Performance
- P20A2Reductant Purge Control Valve A Circuit Low
- P20A4Reductant Purge Control Valve A Stuck Open
- P20A5Reductant Purge Control Valve A Stuck Closed
- P20A6Reductant Injection Air Pressure Control Valve Circuit/Open
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.