Powertrain, generic · Computer and auxiliary outputs

P06A2 Variable A/C Compressor Control Circuit High

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. P06A2 means the control valve circuit is too high – a short to voltage, so a low-side driver cannot pull to ground; with low-side drivers an open valve coil can also appear as 'high'. No manufacturer document available to us names P06A2 itself; the description follows P06A0 and the Ford EVDC system. Cooling is then weak or absent.

Likely causes

Valve control wire shorted to voltage
Valve coil open (seen as 'high' with low-side drivers)
Connector or harness at the compressor damaged
Engine module driver faulty

Symptoms

  • A/C cools weakly or not at all
  • Code stored

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

P06A0P06A1P0647P0645

References: law.cornell.edu, static.nhtsa.gov, patents.google.com.