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.
Scan Tool Data Definitions
The HVAC Scan Tool Data Definitions contains a brief description of all HVAC related parameters available on the scan tool. The list is in alphabetical order. A given parameter may appear in any one of the data lists. In some cases, the parameter may appear more than once or in more than one data list in order to group certain related parameters together.
- PCM - A/C Relay Command
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The scan tool displays On or Off. On is displayed when the PCM has energized the A/C compressor clutch relay.
- PCM - Engine Data 2 - A/C High Side Pressure
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The scan tool displays -103 to +3119 kPa, -14 to +452 psi. This parameter represents the A/C refrigerant pressure sensor voltage signal converted to pressure.
- PCM - Engine Data 2 - A/C High Side Pressure
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The scan tool displays 0 to 5 volts. The output of the A/C refrigerant pressure sensor.
- PCM - Engine Data 2 - A/C Off For WOT
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The scan tool displays Yes or No. Yes indicates that the PCM has disabled the A/C compressor because the TP sensor signal is at wide open throttle.
- PCM - Engine Data 2 - A/C Pressure Disable
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The scan tool displays Yes or No. Yes is displayed when the system pressure exceeds 3034 kPa (440 psi).
- PCM - Engine Data 2 - A/C Request Signal
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The scan tool displays Yes or No. Yes is displayed when the HVAC control module is requesting A/C system operation.
- PCM - Output Driver Data - A/C Relay Circuit Status
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The scan tool displays OK, Fault, or Invalid State. The scan tool indicates the diagnostic state of the A/C relay control circuit.
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.