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U062C Lost Communication With A/C Refrigerant Distribution Valve Actuator C

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

A third distribution valve only exists in elaborate thermal systems that combine cabin cooling, heat pump, dehumidification and battery conditioning in one refrigerant loop. U062C is stored when valve actuator C fails to reply on its serial line. In such layouts several actuators often hang on one LIN segment; if C and D are lost together while A and B still answer, check the common wiring section, splice or supply of that segment before replacing any valve. No manufacturer documents U062C publicly. CARB asks for a dedicated fault for missing communication with digital components only where they are monitored for emissions or other diagnostics, which is rarely the case for cabin climate valves.

Likely causes

Shared LIN segment, splice or supply feeding valve C damaged (often with U062D)
Connector at actuator C loose, wet or corroded
Actuator C electronics failed

Symptoms

  • A single heat-pump or dehumidifying mode no longer works
  • Windows fog more easily in heating mode
  • Climate system warning or reduced comfort without warning

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–900
Time0.5–4 h

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

Parts involved

ac distribution valve actuator cvehicle bus wiring

Related codes

U062AU062BU062D

References: law.cornell.edu, egelhof.com, en.wikipedia.org.