For 1990-2009 cars

# THERMAL EXPANSION VALVE REPL. EXPANSION TUBE (ORIFICE)

#### SUBJECT: INFORMATION BULLETIN - USE OF A THERMAL EXPANSION VALVE IN PLACE OF EXPANSION (ORIFICE) TUBE

VEHICLES AFFECTED: 1992 L/N CARS WITH A/C ------------------------------------------------------------------------------

This is an information bulletin to familiarize technicians on the use of a TXV (Thermal Expansion Valve) for a means of controlling refrigerant flow. The TXV is located inside the heater/evaporator module, attached to the evaporator. The Expansion (Orifice) Tube is no longer used on these models.

The 1992 L/N air conditioning system still uses the V-5 compressor, but have gone to the use of the TXV for specific performance gains. Compressor operation is basically unaffected, however there are major differences in system pressures, performance and diagnosis between the two systems.

IT IS VERY IMPORTANT THAT THE SPECIFIC TXV SYSTEM DIAGNOSIS CHART, AS SHOWN IN SECTION 1B OF THE 1992 L/N SERVICE MANUAL BE USED.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.