P214FReductant Heater A Current Too High
- 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
- P214F concerns heater A of the DEF system, which Ford and GM both assign to the heater inside the tank (heater circuit 1). The code says this element consumed more current or power than intended. Ford's 2023 diesel summary performs one check per heating cycle, right after a cold start, and decides within 2.2 s when tank heater power is higher than expected. GM's 2025 Duramax tables set P214F when heater 1 current passes 15 A in 40 consecutive 100 ms samples; that is Type A and lights the MIL after one trip; the 2015 tables detected a shorted tank heater through a conductance of at least 0.62 S, Type B. A shorted element, wet connector or chafed lead is the usual reason. Without tank heating, frozen DEF thaws late or not at all, so dosing and NOx reduction start late in winter. P21DD is the low-current counterpart.
- What you may notice
- Check engine light on
- DEF system warning in cold weather
- Delayed DEF dosing after cold starts
- Likely causes
- LikelyTank heater element internally shorted (often replaced with the tank sender unit)
- PossibleWater ingress or corrosion in the heater connector
- PossibleChafed heater wiring shorted to ground
- RareFaulty heater driver in the reductant control module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €1,800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.