P05B1Active Grille Air Shutter B Control 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. P05B1 concerns the control or motor coil circuit of actuator B. Ford's 3.0 L diesel reports an open and a shorted coil under it, checked at the start and 500 ms after each movement, fault after 10 s. Toyota's RAV4 Hybrid uses P05B1 as a collective code with failure types for short to positive, short to ground or open, and no signal. GM does not use it.
- What you may notice
- Check engine light on
- Lower shutter inoperative
- Slightly higher consumption, longer warm-up
- Likely causes
- LikelyActuator B coil open or shorted
- PossibleConnector corroded or damaged (lower bumper, splash water)
- PossibleFront harness damaged (impact, chafing, rodents)
- RareModule
- 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: €80 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.