OBD-II code · Powertrain (generic, extended)
P20FC Reductant Pump B Control Circuit Low
DEF pump B control line stuck low — short to ground. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Is it safe to drive with P20FC?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyShort to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
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
Related codes
- P208CReductant Pump A Control Circuit Low
- P20FAReductant Pump B Control Circuit/Open
- P20F9Intake Manifold Runner Control Circuit Performance (Bank 2)
- P20FBReductant Pump B Control Performance/Stuck Off
- P20FDReductant Pump B Control Circuit High
- P20FEReductant Metering Unit 1 Performance
- P20FFReductant Control Module Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.