P20BEReductant Heater B Control Circuit Performance
- 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
- P20BE judges whether heater B, in most designs the heated pressure line, behaves as expected once the wiring itself checks out. GM's 2025 DEF tables flag line heater resistance below 2.80 or above 7.50 ohms, or a power error above 16.5 W, after 8 s (Type A); the 2018 tables accept a voltage-to-current ratio only between 1.51 and 3.57 ohms. Ford tests circuit 2, the pressure line heater, continuously while it heats and fails it when conductance falls below 0.3 S within 2.2 s, in addition to an on/off current and voltage comparison. For the 3.0 L EcoDiesel FCA titles the code Reductant Pressure Line Heater Control Circuit Performance; its 2014 Ram 1500 bulletin cured spurious entries with PCM software. Deutz maps P20BE to over-temperature of its pressure line heater.
- What you may notice
- Malfunction indicator lamp after a heating phase
- Ice in the pressure line on cold starts, dosing late
- Possible NOx efficiency codes as a consequence
- Likely causes
- LikelyPressure line heating wire degraded, resistance outside the window
- PossibleHigh-resistance joint at the line heater connector
- PossibleEngine control software setting the code erroneously (FCA 18-028-14)
- RareLow heater supply voltage distorting the current measurement
- 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: €0 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.