Lost Communication With Active Aerodynamics Module
The U0256 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Active Aerodynamics Module. This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $300 - $1,200 (parts and labor)
Network codes mean modules are not communicating. You need a scanner that reads all systems to find the problem.
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Common Symptoms
- Active grille shutters not operating
- Rear spoiler not deploying at speed
- Underbody aero flaps stuck
- Aerodynamic efficiency warning light
Probable Causes (Ranked by Likelihood)
- Failed active aero actuator Very High
- Aero module communication failure High
- CAN bus wiring fault Moderate
- Debris blocking aero components Low
Step-by-Step Diagnostic Procedure
-
Inspect active aero components for debris
-
Check actuator motor operation
-
Scan active aero module for codes
-
Test CAN bus communication at module
Frequently Asked Questions
Can I drive with U0256?
Yes. Fuel economy may decrease slightly without active aerodynamics.
What causes U0256?
Usually a failed actuator motor or debris blocking the aero components.
What are active aerodynamics?
Movable body panels that adjust at speed to reduce drag and improve efficiency or downforce.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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