The vehicle bus reports loss of communication with active grille shutter module D. The aerodynamic flaps in front of the radiator stay in their default position, increasing drag and possibly affecting cooling.
Medium severity. Can I keep driving?It depends on which control module has dropped out. If it affects the engine, brakes, or steering, do not continue your trip: call for roadside assistance.
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
Most likely causes
- Bus wiring open or shorted
- Module without power or ground
- Module failed
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
What each character of U028C means
- U: Communication network
- 0: Generic code: same on every make
- 2: Subsystem depends on the code range
- 8C: Specific fault in that system
Frequently asked questions
Can I keep driving with code U028C?
It depends on which control module has dropped out. If it affects the engine, brakes, or steering, do not continue your trip: call for roadside assistance.
What causes code U028C?
The most common causes are: bus wiring open or shorted; module without power or ground; module failed.
Related codes
- U028BLost Communication With Active Grille Air Shutter Module C
- U0285Lost Communication With Active Grille Air Shutter Module B
- U0284Lost Communication With Active Grille Air Shutter Module A
Sources
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.