Powertrain, generic · Computer and auxiliary outputs

P06A0 Variable A/C Compressor Control Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Variable-displacement A/C compressors change their swash-plate stroke via an electric control valve: a PWM current sets the crankcase pressure and thus the output. Where the engine module drives this valve (Ford's 'EVDC' compressors 2013–2019), it monitors the circuit; where the climate control module drives it (Hyundai, VW/Audi, GM), faults appear in that module instead. CARB requires monitoring only where the A/C affects engine control. P06A0 is the general circuit fault of the compressor control valve. Ford's service messages for its EVDC compressors (2013–2019) describe it with weak or no cooling, typically from a valve with an open coil or a corroded connector at the compressor; low refrigerant can also mislead the diagnosis. The compressor then runs at minimum stroke or does not cool. Not emission relevant in most cases.

Likely causes

Compressor control valve faulty (coil open)
Connector at the compressor corroded or loose, wire open
Low or incorrect refrigerant charge misleading the diagnosis
Engine module driver faulty

Symptoms

  • A/C cools weakly or not at all
  • Code stored, check engine light usually off
  • Compressor stays at minimum output

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€30–900
Time0.5–3 h

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

Parts involved

ac compressor control valvevalve wiringengine control module

Related codes

P06A1P06A2P0645P0646P0647P0530

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