P2B31Fan 2 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
- P2B31 is the functional code for a second radiator fan: its circuits test fine (otherwise P0481, P0693 or P0694 would be set), yet the fan turns too slowly or not at all when commanded. Twin-fan cooling packs usually run fan 2 for high load or A/C demand, so a failure tends to show up only in heat or traffic. No manufacturer documents P2B31 publicly. FCA's 2.0 L Alfa Romeo models use the fan 1 sibling P2B2F with the MIL, and Audi's e-tron GT bulletins show how debris from the wheel housing can jam either of its two fans. CARB requires output components to be monitored for functional response where feasible. A worn motor, blocked blades or a fan module that stays off are the likely causes. Expect rising temperatures under load. Its stuck-on twin is P2B32.
- What you may notice
- MIL or cooling warning
- Temperature climbing at high load or with A/C on
- Likely causes
- LikelyFan 2 motor worn, seized or jammed by debris
- PossibleFan module or relay for fan 2 not switching on
- RareWeak supply or ground to fan 2
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €20 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.