For 1990-2009 cars

# SERVICE MANUAL UPDATE-SEC. 1B A/C SYS. EVACUATION USING ACR4

#### Subject: SERVICE MANUAL UPDATE - SECTION 1B - A/C SYSTEM EVACUATION USING ACR4 Models Affected: 1993 TRANS SPORT AND FIREBIRD MODELS

This bulletin serves to cancel and supersede the first paragraph of the "Evacuation" procedures under "Refrigerant Recovery and Recycling, Adding Oil, and Evacuation and Recharging Procedures" in Section 1B of all 1993 Trans Sport and Firebird Service Manuals. The first paragraph under "Evacuation" should read as follows:

The ACR4 unit tank must contain sufficient R-134a refrigerant for A/C system charging. Check the amount of refrigerant in the tank by simultaneously pressing "RESET" and "ENTER" on the keypad to enter the diagnostic mode. Once in the diagnostic mode, press "7". When "7" is pressed, the ACR4 unit will display the amount of R-134a refrigerant available in the tank. If less than 3.6 kg (8 lbs.) is displayed, add new refrigerant to the tank. Refer to the manufacturer's instructions for adding refrigerant.

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.