P05B5Active Grille Air Shutter B Supply Voltage Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- 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. P05B5 means the battery supply of actuator B via fuse or relay is missing or open; without it there is no movement, and smart actuators drop off the LIN bus. No manufacturer document available to us uses this code, like its shutter A counterpart. VW's check measures supply and ground at the actuator connector; GM feeds its actuators via a relay but uses other codes.
- What you may notice
- Check engine light on
- Lower shutter inoperative
- Possibly also U0285
- Likely causes
- LikelyFuse blown or relay faulty
- PossibleBroken wire or connector off in the lower front end
- PossibleGround connection open
- RareActuator faulty internally
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €10 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.