An active grille shutter closes louvres in the grille to cut drag and speed warm-up and opens them for cooling; CARB names it as an off-cycle CO2 technology and treats the actuator as an output component. Smart actuators (Ford 3.0 L diesel, Toyota) check their own coil and supply and report over LIN; simpler ones (VW 1.8 T) have their own supply and a control line from the engine module. GM uses none of P05A2–P05A8. A fault usually only costs fuel and warm-up time. P05A6 means the actuator's battery supply via fuse or relay is missing or open; without supply there is no movement, and smart actuators also drop off the LIN bus (U0284). No manufacturer document available to us uses this code. GM feeds its actuator via a relay but uses other codes.
Medium severity. Can I keep driving?If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
Symptoms
- Check engine light on
- Shutter inoperative
- Possibly also U0284
Most likely causes
- Fuse blown or relay faulty
- Broken wire or connector off in the front end
- Actuator ground open
- Actuator faulty internally
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: easy
- It affects emissions.
What each character of P05A6 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 5: Speed and idle
- A6: Specific fault in that system
Frequently asked questions
Can I keep driving with code P05A6?
If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
What causes code P05A6?
The most common causes are: fuse blown or relay faulty; broken wire or connector off in the front end; actuator ground open.
Related codes
- P05A7Active Grille Air Shutter A Supply Voltage Circuit Low
- P05A8Active Grille Air Shutter A Supply Voltage Circuit High
- P05A2Active Grille Air Shutter A Control Circuit/Open
- U0284Lost Communication With Active Grille Air Shutter Module A
- P05B5Active Grille Air Shutter B Supply Voltage Circuit/Open
Sources
- law.cornell.edu: 13 CCR 1968.2
- static.nhtsa.gov: MC 10121130 9999
- gsi.ext.gm.com: 19OBDG03B Diagnostics
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.