For 1990-2009 cars

# POOR TEMP CONTROL FROM HVAC SYSTEM (DIAG./SERVICE PROC.)

#### SUBJECT: POOR TEMPERATURE CONTROL FROM HVAC (DIAGNOSE/SERVICE PROCEDURE)

#### MODELS: 1994 OLDSMOBILE NINETY EIGHT AND EIGHTY EIGHT WITH DUAL ZONE HVAC - RPO CJ2

#### CONDITION:

SOME OWNERS MAY COMMENT ON POOR TEMPERATURE CONTROL FROM THE HVAC SYSTEM.

#### CAUSE:

THERE ARE THREE KNOWN CAUSES FOR THE ABOVE CONDITION. THEY ARE:

1. THE SOLAR SENSORS MAY NOT BE PROPERLY POSITIONED. 2. THE IN-VEHICLE TEMPERATURE SENSOR MAY NOT BE PROPERLY INSTALLED. 3. THE DRIVER'S SIDE TEMPERATURE VALVE LINKAGE MAY BE OUT OF ADJUSTMENT.

#### CORRECTION:

#### CAUTION:

WHEN PERFORMING SERVICE ON OR AROUND SUPPLEMENTAL INFLATABLE RESTRAINTS (SIR) COMPONENTS OR SIR WIRING, FOLLOW PROCEDURES IN THE SERVICE MANUAL, SECTION 9J, TO TEMPORARILY DISABLE THE SIR SYSTEM. REFER TO THE APPROPRIATE SERVICE MANUAL PROCEDURES. FAILURE TO FOLLOW PROCEDURES COULD RESULT IN POSSIBLE AIR BAG DEPLOYMENT, PERSONAL INJURY, OR UNNEEDED SIR SYSTEM REPAIRS.

1.) SOLAR SENSOR ORIENTATION - (SEE FIGURE 1)

TO CHECK IF THE SOLAR SENSORS ARE IN THE PROPER ORIENTATION, LOOK DOWN THROUGH THE WINDSHIELD AND IDENTIFY THE LOCATOR TABS OF THE SOLAR SENSOR. THE LARGER TABS OF THE SENSORS SHOULD BE POINTED TOWARD EACH OTHER. THE TABS SHOULD ALSO BE UP AGAINST THE STOP BLOCK.

IF THE SENSORS ARE NOT PROPERLY POSITIONED, REMOVE THE DEFROSTER GRILL AS DESCRIBED IN SECTION 1C OF THE SERVICE MANUAL. THE SOLAR SENSORS CAN THEN BE TURNED INTO THEIR PROPER POSITIONS.

2.) IN-VEHICLE TEMPERATURE SENSOR - (SEE FIGURE 2)

THE IN-VEHICLE TEMPERATURE SENSOR MAY NOT BE PROPERLY SEALING AT THE KNEE BOLSTER. IF THE SENSOR IS NOT SEALING PROPERLY, IT WILL BE SENSING THE AIR TEMPERATURE FROM BEHIND THE I/P, WHICH WILL CAUSE THE HVAC SYSTEM TO OVER HEAT OR OVER COOL THE PASSENGER COMPARTMENT. TO CHECK THE OPERATION OF THE IN-VEHICLE TEMPERATURE SENSOR, VERIFY THAT THE ASPIRATOR GRILL WILL HOLD A 45MM X 45MM (1.75" X 1.75") PIECE OF 20# BOND PAPER (TYPICAL COPIER PAPER) WHEN THE BLOWER SPEED IS SET TO THREE BARS.

IF THE ASPIRATOR GRILL WILL NOT HOLD THE PIECE OF PAPER, VERIFY THAT THE FOAM SEAL IS PROPERLY INSTALLED AND THAT BOTH TABS OF THE IN-VEHICLE TEMPERATURE SENSOR ARE PROPERLY SECURED TO THE KNEE BOLSTER AS DESCRIBED IN SECTION 1C OF THE SERVICE MANUAL.

3.) DRIVER TEMPERATURE VALVE LINK - (SEE FIGURE 2)

WHEN THE TEMPERATURE VALVE LINK IS OUT OF ADJUSTMENT, THE OWNER CONCERN MAY BE THAT THE DRIVER'S SIDE OF THE VEHICLE SEEMS HOT OR COLD, OR THAT THERE IS A GREAT TEMPERATURE DIFFERENCE BETWEEN THE DRIVER AND PASSENGER SIDES. TO IDENTIFY IF THE LINK IS OFF OR OUT OF ADJUSTMENT, PUSH BACK THE RUBBER STOPPERS IN THE GLOVE COMPARTMENT ALLOWING THE GLOVE COMPARTMENT TO SWING DOWN. WITH THE GLOVE COMPARTMENT OUT OF THE WAY, YOU CAN SEE THE LINKAGE.

TO ADJUST THE TEMPERATURE VALVE LINK:

1. TURN IGNITION "ON". 2. SET TEMPERATURE CONTROL TO 90 DEGREES FAHRENHEIT (32 DEGREES CELSIUS) 3. WAIT FOR PROGRAMMER ARM TO FINISH TRAVELING TO FULL HOT POSITION. 4. PULL HVAC CASE ROD TO THE RIGHT UNTIL A LIGHT RESISTANCE IS FELT. 5. PULL PLASTIC LOWER LINK TO THE LEFT UNTIL SLACK IS REMOVED AND ATTACH TO HVAC CASE ROD.

#### WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER: D0005 LABOR TIME: 0.2 HR. (PERFORMANCE CHECK) ADD: 0.1 HR. (TO REPOSITION SOLAR SENSORS) ADD: 0.5 HR. (TO REPOSITION IN-VEHICLE TEMPERATURE SENSOR) ADD: 0.1 HR. (TO ADJUST DRIVER'S TEMPERATURE LINKAGE)

FIGURES: 2

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.

COPYRIGHT 1994 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.