Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Pinpoint Test S: P06A0
- Refer to Wiring Diagrams AUTOMATIC CLIMATE CONTROL SYSTEM
for schematic and connector information.
Normal Operation and Fault Conditions
The externally controlled variable displacement compressor is electronically controlled by the PCM. The PCM pulse width modulates the ground to the externally controlled variable displacement compressor to change the displacement of the A/C compressor. REFER to: Climate Control System - Vehicles With: Dual Automatic Temperature Control (DATC) - System Operation and Component Description .
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition PCM P06A0:00 Variable A/C Compressor Control Circuit: No Sub Type Information This DTC sets when the PCM senses unexpected voltage on the sensor feedback circuit, indicating a short to voltage, an open circuit or an open sensor. Possible Sources
- Fuse
- Wiring, terminals or connectors
- A/C system discharged or low refrigerant charge
- A/C compressor
- PCM
Visual Inspection and Pre-checks
- Inspect for loose or corroded A/C compressor connections.
- Make sure BJB fuse 8 (10A) is OK.
- NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.
- S1 EXTERNALLY CONTROLLED VARIABLE DISPLACEMENT COMPRESSOR (EVDC) PERFORMANCE CHECK WITH THE AC COMPRESSOR ELECTRONIC CONTROL VALVE TESTERNOTE: The following pinpoint test step uses the EVDC100 Electronic Variable Displacement A/C Compressor Control Valve Tester, available on the Ford Rotunda website.NOTE: Proper Air Conditioning (A/C) system diagnosis on a vehicle's compressor is dependent on correct refrigerant system charge and tested in ambient temperatures above 21.1 deg.C (70 deg.F).
- Test the EVDC compressor displacement, following the instructions in the user manual supplied with the Model EVDC100 A/C Compressor Electronic Control Valve Tester.
Did the suction low side pressure decrease or the high side pressure increase?
Yes The Externally Controlled Variable Displacement Compressor (EVDC) is able to change the displacement. Do not replace the compressor. If DTC P06A0 is present, GO to S2 If DTC P06A0 is not present, CHECK refrigerant charge amount. REFER to the appropriate GENERAL PROCEDURES . No GO to S2 - S2 CHECK FOR VOLTAGE TO THE A/C (AIR CONDITIONING) COMPRESSOR DISPLACEMENT CONTROL VALVE
- Ignition OFF.
- Disconnect Externally controlled variable displacement compressor C1110.
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead C1110-1 Ground
Is the voltage greater than 11 volts?
Yes GO to S3 No VERIFY BJB fuse 8 (10A) is OK.If OK, REPAIR the circuit.If not OK, REFER to the OEM WIRING DIAGRAMS to identify the possible causes of the circuit short. - S3 CHECK THE A/C (AIR CONDITIONING) COMPRESSOR DISPLACEMENT CONTROL VALVE CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect PCM, 2.7L C1232B, 3.3L C1551B, 3.5L C175B, 5.0L C1381B or 3.0L Power Stroke Diesel C1233B.
- Measure:
Positive Lead Measurement / Action Negative Lead C1110-2 Ground
Is the resistance greater than 10, 000 ohms?
Yes GO to S4 No REPAIR the circuit. - S4 CHECK THE A/C (AIR CONDITIONING) COMPRESSOR DISPLACEMENT CONTROL VALVE CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead C1110-2 Ground
Is any voltage present?
Yes REPAIR the circuit. No GO to S5 - S5 CHECK THE A/C (AIR CONDITIONING) COMPRESSOR DISPLACEMENT CONTROL VALVE CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure:
2.7L
Positive Lead Measurement / Action Negative Lead C1110-2 C1232B-10 3.3L
Positive Lead Measurement / Action Negative Lead C1110-2 C1551B-10 3.5L
Positive Lead Measurement / Action Negative Lead C1110-2 C175B-10 5.0L
Positive Lead Measurement / Action Negative Lead C1110-2 C1381B-10 3.0L Power Stroke Diesel
Positive Lead Measurement / Action Negative Lead C1110-2 C1233B-65
Is the resistance less than 3 ohms?
Yes INSTALL a new A/C compressor. REFER to the appropriate procedure in the appropriate Climate Control System article. CLEAR the DTC and REPEAT the PCM self-test. If the DTC returns, GO to S6 No REPAIR the circuit. - S6 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect all PCM electrical connectors (if not previously disconnected).
- Repair:
- corrosion (install new connector or terminal - clean module pins)
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary
- Connect all PCM electrical connectors. Make sure they seat and latch correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, Refer to PCM GUIDED ROUTINE TESTING No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.