Powertrain, generic

P0EC9 A/C Refrigerant Distribution Valve A Stuck/Open

Check engine lightOn

EmissionsNot relevant

Drive cycleNot required

Limp modeNo

P0EC9 reports that refrigerant distribution valve A, a solenoid valve that splits refrigerant between branches of the A/C circuit, stays open or does not close on command. Such a fault is usually detected indirectly, because pressure or temperature behind the valve fails to react when it should be shut. Audi uses the code on the 2016 A3 Sportback e-tron: P0EC900 is logged passive/sporadic in the Climatronic module J255, and the MIL is switched on at the request of another module over the network, so the engine module J623 holds no code. Bulletins 2046942 and 2047037 trace it to a miscalculation in the refrigerant self-test and call for new J255 software; if the code returns after erasing, it has to be diagnosed as a real fault. Circuit faults of valve A are P2611 to P2613, valve B stuck open is P0EE2.

Likely causes

Faulty self-test calculation in the climate control software (Audi A3 e-tron, fixed by update)

Valve held open by dirt, debris or a sticking armature

Weak solenoid coil that no longer pulls the valve fully shut

Symptoms

MIL on without a code in the engine control module
Code stored passive/sporadic in the climate control module
Reduced or uneven cooling in one branch, or no noticeable change at all

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€0–600

Time0.3–3 h

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

Parts involved

ac refrigerant distribution valve ahvac control module

References: static.nhtsa.gov, static.nhtsa.gov, law.cornell.edu.