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U065E Lost Communication With Ram Air Actuator

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

At speed, the wind pushes extra outside air through the cowl inlet into the climate housing. Some vehicles therefore fit the fresh-air path with a motorised ram air flap that narrows the opening as dynamic pressure rises, so airflow and noise stay steady; Behr's US 5,645,479 nests it with the recirculation flap, and Daimler's DE 10 2010 025 623 drives it through a non-linear linkage for fine throttling near closed. Others, like Honda in WO 2012/115719, use the inlet door for the same job and have no separate flap. U065E means the master has lost its LIN link to that flap's actuator. No maker documents the code publicly. A flap stuck open lets the cabin airflow surge and rush at motorway speed; one stuck nearly shut starves the vents at low speed.

Likely causes

Ram air flap actuator electronics failed
Moisture or debris from the cowl reaching the actuator connector
LIN wire to the ram air actuator chafed or disconnected

Symptoms

  • Airflow rises noticeably with road speed
  • Air rush noise from the vents at high speed
  • Weak airflow at low speed if the flap stopped nearly closed

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–400
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

ram air actuatorvehicle bus wiring

Related codes

U065DU0164B0173

References: patents.google.com, patents.google.com, patents.google.com.