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U062E Lost Communication With A/C Refrigerant Expansion Valve Actuator

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

An electronic expansion valve uses a geared or stepper motor to set the refrigerant flow into an evaporator or battery chiller, guided by pressure and temperature readings instead of a thermostatic bulb. Units such as Egelhof's EXV and KXV accept their target position over LIN and carry a position sensor, so they can also shut a branch completely. U062E is logged when that actuator stops answering. No manufacturer documents U062E publicly. The consequences can reach the drivetrain: on Mercedes EQE and EQS models (series 294 to 297) a faulty chiller expansion valve Y140/1 triggered a cooling-system warning announcing reduced energy input, though there the valve hung open (code B3A0077) rather than going silent. Distribution valves are covered by U062A to U062D.

Likely causes

LIN, supply or ground wire to the expansion valve damaged
Connector at the valve wet or corroded (often near the evaporator or chiller)
Expansion valve motor electronics failed
Software fault in the thermal or powertrain controller

Symptoms

  • No cooling at the affected evaporator or chiller
  • Cooling-system warning, possibly reduced drive or charging power on electrified vehicles
  • Heat pump unavailable

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–1,000
Time1–4 h

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

Parts involved

ac expansion valve actuatorvehicle bus wiring

Related codes

U062AU062BU0626U0627

References: egelhof.com, egelhof.com, static.nhtsa.gov, en.wikipedia.org.