This standard establishes the minimum requirements for an internal heat exchanger (IHX) assembly to be used in R134a, GMW5038 and R1234yf, GMW16283 Air Conditioning (A/C) systems.

Supplier qualification shall be demonstrated for the IHX design before the supplier may bid on IHX business. To obtain qualification, the supplier's IHX design shall meet all requirements of this specification and shall be approved by the General Motors Bill of Material (BOM) Family Owner (BFO).

This standard does not include the IHX validation requirements for: brazed/welded fittings, access ports, etc., (covered in GMW15787), Air Conditioning Refrigerant System Connections (covered in GMW15787), internal cleanliness (covered in GMW14319) or seal washers (covered in GMW15779). In addition, this specification does not include the validation requirements for larger assemblies containing an IHX. IHX production assembly parts shall be in accordance with metallic refrigerant lines GMW15773, and lines containing elastomeric hose, or coupled hose assemblies shall fulfill GMW14319.