OBD-II fault code

U0290: Lost Communication With Active Aerodynamic Feature Control Module D

What it means

The vehicle bus reports loss of communication with active aerodynamic feature module D. Powered spoilers, air-dams or wheel-arch closures controlled by this node default to a fixed position.

How it works

Active aerodynamic feature control module D operates a powered aerodynamic device assigned to that node, such as a spoiler, air dam or wheel-arch closure. Other modules expect it to send status messages over the vehicle network; this code sets when those messages stop arriving for the required time.

Common causes

Most likely first.

  1. Bus wiring open or shorted
  2. Module without power or ground
  3. Module 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

How to diagnose it

  1. Scan all modules for communication codes and freeze-frame details to see whether module D alone dropped offline or several modules lost network messages together.
  2. Check whether the module D aerodynamic feature is stuck or inoperative, and inspect its connector and nearby harness for looseness, water, corrosion or damage.
  3. Using the wiring diagram, check that module D has the specified power and ground, since a supply fault can make it disappear from the network.
  4. Inspect and test the network wiring to module D for opens, shorts or poor connections, following the manufacturer's procedures.
  5. If power, ground and network wiring are sound, confirm the fault is current and assess module D for failure using manufacturer diagnostic procedures.

Common fixes

  • Reconnect or repair a loose, corroded or water-damaged module D connector.
  • Repair an open or short in the network wiring serving module D.
  • Restore the module's specified power or ground by repairing its feed, fuse or ground connection as indicated by testing.
  • Replace module D only after its power, ground and network connections test correctly.

Can I keep driving?

If the vehicle drives and steers normally, a short trip may be possible, but the module D spoiler, air dam or other feature may remain in a fixed position and reduce aerodynamic performance. Avoid high-speed driving if the feature is visibly loose or obstructing airflow, and stop if other warnings affect vehicle control.

A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together

This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.

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