For 1990-2009 cars

# INFO. ON TECH2 DATA FOR A/C LOW TEMP. SWITCH READS HIGH

THIS IS A MONTHLY SERVICE NEWSLETTER ARTICLE. THIS BULLETIN IS NOT INTENDED FOR PUBLICATION.

#### SUBJECT: INFORMATION ON TECH2 DATA FOR A/C LOW TEMPERATURE SWITCH READS HIGH. (INSTALL THE LAST 1997 CD INFORMATION INTO THE TECH2).

#### MODELS: 1996-1997 RIVIERA

(1) A/C LOW SIDE TEMPERATURE SWITCH DATA READS HIGH (ABOVE 100 DEGREESF.) WITH THE TECH2 AND A/C OPERATION IS O.K. (2) A/C COMPRESSOR CLUTCH CYCLES BEFORE A/C GETS COLD AND LOW TEMPERATURE SWITCH DATA LOOKS NORMAL (BETWEEN 42 - 48 DEGREES F.). NO DTCS WILL BE STORED

LATER VERSIONS OF TECHLINE SOFTWARE RELEASES HAVE SKEWED THE A/C LOW SIDE TEMPERATURE SWITCH DATA FOR THESE VEHICLES. NORMAL DATA SHOULD READ BETWEEN 42 - 48 DEGREES F. AFTER THE SYSTEM HAS NORMALIZED. CURRENT TECH2 SOFTWARE RELEASES WILL CAUSE THIS READING TO SHOW ABOVE 100 DEGREES F. WHEN THE SYSTEM IS OPERATING NORMALLY. A FAILED LOW TEMPERATURE SWITCH MAY SHOW NORMAL TEMPERATURES WHEN ACTUAL TEMPS ARE FALLING BELOW 22 DEGREES F. AND CYCLING THE COMPRESSOR CLUTCH.

TO PROPERLY READ LOW SIDE A/C TEMPERATURE SWITCH DATA INSTALL LATE 1997 TECH2 SOFTWARE FROM CD VERSION (17.016 OR EARLIER).

#### NOTE: TECHLINE HAS BEEN NOTIFIED AND IT IS NOT KNOWN WHICH 97 CD WILL CORRECTLY READ DATA.

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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.

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