Network, generic

U062B Lost Communication With A/C Refrigerant Distribution Valve Actuator B

Check engine lightUsually off

EmissionsNot relevant

Drive cycleNot required

Limp modeNo

Valve B is a further refrigerant switching point, for instance one that opens or closes a rear evaporator or a battery chiller path; the assignment of letters differs from maker to maker. U062B records that actuator B has stopped responding to its digital commands. While A still answers, the shared LIN master and the main feed are probably sound and the search narrows to B's branch. Egelhof's multi-way valve shows another design: one LIN-controlled motor unit with up to seven positions takes the place of up to four solenoid valves, so a single silent actuator can block several flow paths at once. No manufacturer documents U062B publicly. P0EE3 to P0EE6 cover the electrical circuit of valve B and P0EE2 a stuck valve.

Likely causes

Wiring fault in the branch to valve actuator B

Loose or corroded connector at actuator B

Actuator B electronics or motor unit failed

Symptoms

One cooling branch (rear A/C or battery chiller) does not work
Several heat-pump modes unavailable at once with a multi-way valve
Thermal system warning message

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 bvehicle bus wiring

References: egelhof.com, egelhof.com, law.cornell.edu.