P05AFActive Grille Air Shutter B Stuck On
- 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
- Shutter B is the second active grille shutter – at GM, Ford and Stellantis the lower one in the bumper. Shutters cut drag and speed warm-up when closed and open for cooling; CARB names them as an off-cycle CO2 technology and treats the actuator as an output component. Smart actuators report over LIN (loss of communication: U0285); a fault usually costs fuel and warm-up time, a closed shutter can make the engine run hot under load. P05AF is the counterpart of P05AE: shutter B stuck open. Documented only in the VW group – Audi's 2022–24 A3, S3 and RS3 describe it internally as 'grille shutter 2 sticks open' and limit top speed to 100 mph on a shutter fault; the warning was sometimes set by engine module software. GM, Ford and Stellantis report everything under P05AE.
- What you may notice
- Check engine light on
- Grille shutter warning, top speed limited (Audi)
- Longer warm-up, slightly higher consumption
- Likely causes
- LikelyEngine module software (sporadic false message)
- PossibleLouvres blocked open (ice, dirt, debris, accident damage)
- PossibleActuator or shutter unit B faulty
- RarePoor supply or ground at the actuator
- 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 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.