OBD-II code · Powertrain (generic, extended)
P20FA Reductant Pump B Control Circuit/Open
The control line driving DEF pump B is open. On large engines or dual-tank systems a second pump (B) supplements pump A; with B offline the system loses redundancy.
Is it safe to drive with P20FA?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyPump motor 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
- 1–3.5 h
- Emissions test
- Likely to fail
- Parts involved
- Reductant Pump, Reductant Pump Relay
Related codes
- P208AReductant Pump A Control Circuit/Open
- P20F7Reductant Injection Valve Stuck Open (Bank 2 Unit 1)
- P20F8Intake Manifold Runner Control Circuit Performance (Bank 1)
- P20F9Intake Manifold Runner Control Circuit Performance (Bank 2)
- P20FBReductant Pump B Control Performance/Stuck Off
- P20FCReductant Pump B Control Circuit Low
- P20FDReductant Pump B Control Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.