OBD-II code · Network
U0285 Lost Communication With Active Grille Air Shutter Module B
The vehicle bus reports loss of communication with active grille shutter module B. The aerodynamic flaps in front of the radiator stay in their default position, increasing drag and possibly affecting cooling.
Is it safe to drive with U0285?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyBus wiring open or shorted
- PossibleModule without power or ground
- PossibleModule failed
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–2 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Active Grille Shutter Module B, Vehicle Bus Wiring
Related codes
- U0284Lost Communication With Active Grille Air Shutter Module A
- U028BLost Communication With Active Grille Air Shutter Module C
- U028CLost Communication With Active Grille Air Shutter Module D
- U027BLost Communication With Battery Charger Control Module D
- U027CLost Communication With Off-Board Charger Control Module
- U0286Lost Communication With Radiator Anti-Tamper Device
- U0287Lost Communication With Transmission Fluid Pump Module A
- U0288Lost Communication With DC/AC Converter Control Module A
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.