P20FBReductant Pump B Control Performance/Stuck Off
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P20FB is the functional check of reductant pump B: its circuit is electrically sound, yet the pump does not reach the commanded state or stays off when it should be running. No public threshold exists for pump B. For pump A, Ford's 2023 diesel summary flags P208B when pump speed misses its setpoint by more than 300 rpm or the speed control sits at its limit for 30 seconds, which shows the principle. FCA names P20FB Reductant Pump 2 Control Performance and has listed it in a series of PCM reflash bulletins for the 3.0L EcoDiesel in Ram 1500, Wrangler and Gladiator (2020–2021, e.g. 18-028-21 and 18-002-23), so on those trucks a software update comes before any parts. Genuine causes are a worn, frozen or blocked pump or a clogged filter.
- What you may notice
- Malfunction indicator lamp on
- DEF system warning, possibly with countdown to restart lockout
- Code returns mainly after cold starts or long parking
- Likely causes
- LikelyOutdated PCM software (FCA 3.0L EcoDiesel, reflash bulletins)
- PossiblePump B worn, seized or blocked by crystallised fluid
- PossibleFrozen DEF or failed tank heating in cold weather
- RareClogged pump filter or restricted lines
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.