Compressor Anti-Slugging Strategy (CASS)

Liquid refrigerant may accumulate in the A/C compressor under certain conditions. To alleviate damage to the A/C compressor, the compressor anti-slugging strategy (CASS) is utilized.

CASS is initiated only under specific conditions:

• The ignition is off for more than 8 hours
• The ambient temperature is above -4°C (25°F)
• Battery voltage is above 8.5 volts during engine cranking

When these conditions are present, the powertrain control module (PCM) will activate the A/C control relay prior to the engine cranking. The A/C control relay engages the A/C compressor for approximately 4-15 revolutions of the A/C compressor or a maximum of 2 seconds (depending upon vehicle application), allowing the liquid refrigerant to be pushed from the A/C compressor. CASS is initiated by the PCM regardless of the function selector switch position.