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U05C1 Invalid Data Received From Active Radiator Air Flow Control Module A

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

Besides shutters in the visible grille, some cars meter cooling air with flaps placed directly in front of the radiator, behind the bumper intake. Hyundai's patent US11225900B2 describes such an arrangement with two adjacent flaps between bumper opening and radiator plus an air guide steering air towards them. The J2012 list gives this unit its own module family, separate from the grille shutters, and U05C1 means module A delivers position or status frames that the engine or thermal controller rejects. No manufacturer documents U05C1 or its partner U02C0 publicly, so the threshold and lamp strategy are unknown. Because CARB treats active aerodynamic and warm-up devices as off-cycle CO2 technologies, a maker may handle the fault like the shutter codes; in practice the flap is parked open for safe cooling.

Likely causes

Flap actuator A electronics faulty

Connector behind the bumper wet or corroded

Flap blocked by debris or ice so the actuator reports implausible positions

Symptoms

Warning lamp on some vehicles
Flap stays open, slightly higher consumption

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€80–600

Time0.5–2.5 h

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

Parts involved

active radiator airflow module a

Related codes

U02C0 U0585

References: patents.google.com, law.cornell.edu, valeo.com.