P06A2 Variable A/C Compressor Control Circuit High
OBD-II Trouble Code Technical Description
Variable A/C Compressor Control Circuit High
What does that mean?
This is a generic powertrain diagnostic trouble code (DTC) and applies to many OBD-II vehicles (1996-newer). That may include but is not limited to vehicles from General Motors, Honda, Dodge, Ford, BMW, Mercedes, etc. Although generic, the exact repair steps may vary depending on year, make, model and powertrain configuration.
OBD-II trouble codes P06A0, P06A1, and P06A2 are associated with the variable air conditioning (A/C) compressor control circuit.
The purpose of the variable A/C compressor control circuit is to engage and disengage the compressor at the appropriate time to maintain the desired temperature within the vehicle cabin. The ECU receives voltage signals from various components to detect possible malfunctions within the system.
The variable A/C compressor control circuit incorporates several components to accomplish this process. Most newer automobiles are equipped with climate control that is an essential component for this circuit to function properly.
When the Engine Control Unit (ECU) detects abnormally high electrical signals within the variable A/C compressor control circuit code P06A2 will be set and the check engine light will be activated.
A typical air conditioning compressor:
What is the severity of this DTC?
The severity of this code is moderate to severe based on the specific nature of the problem. Although it is a user convenience feature, A/C malfunctions may progress leading to extensive repair requirements when not corrected in a timely manner.
What are some of the symptoms of the code?
Symptoms of a P06A2 trouble code may include:
Air conditioner will not operate properly Check engine light illuminatedWhat are some of the common causes of the code?
Causes for this P06A2 code may include:
Defective A/C compressor Defective A/C solenoid (if applicable) Low or overcharged system Clogged orifice tube or dryer Malfunctioning climate control Defective A/C relay Blown fuse or fuse-able link (if applicable) Corroded or damaged connector Faulty or damaged wiring Defective ECUWhat are some P06A2 troubleshooting steps?
The first step in the troubleshooting process for any malfunction is to research the Technical Service Bulletins (TSB's) for the specific vehicle by year, model and power plant. In some circumstances this can save a lot of time in the long run by pointing you in the right direction.
The second step is to locate all components within this circuit and perform a thorough visual inspection to check the associated wiring for obvious defects such as scraping, rubbing, bare wires, or burn spots. Next is to check the connectors for security, corrosion and damaged pins. This process must include the A/C compressor, associated sensors, relays and the ECU.
Advanced Steps
The advanced steps become very vehicle specific and require the appropriate advanced equipment to perform accurately. These procedures require a digital multi meter and the specific technical references for the vehicle. The ideal tool for this troubleshooting process is an A/C diagnostic machine, if available.
This specialized equipment is essential to pinpoint the source of the malfunction by identifying leaks and verifying appropriate pressures within the system. High and low side gauges will also validate the integrity of the A/C compressor and associated components. Restrictions within the system such as a clogged orifice tube or dryer will also be identified. The appropriate amount of refrigerant in the system plays a key role in the operation of this circuit as well. Safety switches, fuses and fuse-able links are often incorporated to prevent damage to the A/C compressor.
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