GM Service Manual Online
For 1990-2009 cars only

Notice: The refrigeration system on these models uses R-134a which is not compatible with refrigerant R-12. Before servicing the system always make sure the proper servicing equipment is used or the system could become severely damaged. Always refer to the service text and manufacturer's instructions included with service equipment before proceeding.

Two different air conditioning systems are available depending upon the engine application:

  1. The Variable Displacement Orifice Tube (VDOT) refrigerant system is used on vehicles that are equipped with 2.2L engines. These systems use the constant run Harrison V7 compressor.
  2. The Cycling Clutch Orifice Tube (CCOT) refrigerant system is used on vehicles that are equipped with 4.3L engines. These systems use the fixed displacement Harrison HT6 compressor.