U0284Lost Communication With Active Grille Air Shutter Module A
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The grille shutter actuator is a LIN node of the engine controller. GM's 2018 ECM tables set U0284 when the ECM loses the LIN link to shutter 1 for 3 counts in Run with at least 11 V; it is Type B, MIL after two trips. Ford's 2024 OBD summary lists it as a continuous monitor: entry 5 s after start at 11–16 V, fault when the AGS signal is missing over 10 s. A 2020 Volkswagen analysis list treats a lit MIL with U0284 in the ECM as its own case. Water is the common cause: Subaru 07-140-18 (2017–2019 Impreza, connector B63), Ford SSM 46857 (C-Max, C1651), Hyundai 23-01-075H (Ioniq 5 actuator). Several Ford SSMs pair U0284 with generator codes U012D/U042E. Shutters stop moving; engine warm-up and drag suffer.
- What you may notice
- Malfunction indicator lamp on
- Grille shutter warning, shutters do not open or close
- Check charging system message when a shared connection is affected
- Likely causes
- LikelyWater intrusion and corrosion at the shutter actuator connector or its harness
- PossibleFault on a shared connection, e.g. with the generator (check U012D/U042E)
- PossibleUnstable power supply to the actuator
- RareShutter actuator A internally faulty or damaged by impact
- 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: €30 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.