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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Corvette 🢒 Body and Accessories 🢒 Wiring Systems 🢒 HVAC System Check

HVAC System Check C60


Object Number: 106094 Size: SF

HVAC System Check (C60)

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Install the scan tool.
  2. Turn the ignition switch to the ON position.
  3. Select display DTC function with the scan tool.
  4. Check for any stored PCM or BCM DTCs related to HVAC operation.

No DTCs are stored in memory or current status.
    • DTC is stored in memory or current status (refer to appropriate DTC table).

2
  1. Turn ignition to the OFF position.
  2. Remove the scan tool from the diagnostic link connector.
  3. Start the engine and allow the vehicle to idle in Park until the engine reaches operating temperature.
  4. Close the vehicle doors and windows.
  5. Engine decklid in the closed position.
  6. Turn the HVAC mode control knob to the instrument panel UPPER position.
  7. Turn the blower switch to position three.
  8. Turn the temperature control knob to the maximum hot position.
  9. Press the A/C button so that it is in the OFF position.
  10. Press the OUTSIDE AIR button to the ON position.
  11. Install an accurate thermometer into the UPPER air outlet.
    • Air flows from the instrument panel outlets.
    • A/C is disengaged.
    • Hot air is delivered to passenger compartment.
    • Blower fan operates at medium speed.
    • Delivered air temperature is approximately between 63°C and 68°C (145°F and 155°F) measured in typical garage settings (21°C to 24°C (70°F to 75°F)).
    •  Air Delivery Improper
    •  Heating Insufficient

3
  1. Close all doors and windows.
  2. Engine decklid in the closed position.
  3. Turn the temperature control knob to the maximum cold position.
  4. Depress the A/C button to the ON position.
  5. Depress the RECIRC button.
  6. Turn the blower switch to position 3.
  7. Install a thermometer into the UPPER air outlet.
    • Air flows from the instrument panel outlets.
    • A/C light illuminates and compressor is engaged.
    • Cold air is delivered to passenger compartment.
    • Blower fan operates at medium speed.
    • Delivered air temperature is approximately 18°C (30°F) lower than ambient temperature.
    •  Air Delivery Improper

4
  1. Depress the A/C button to the OFF position.
  2. Depress the OUTSIDE AIR button.
    • Air flows from the instrument panel outlets.
    • A/C is disengaged.
    • Outside air (ambient temperature) is delivered to passenger compartment.
    • Blower fan continues to operate at moderate speed.
    •  Air Delivery Improper

5
  1. Turn the HVAC mode control knob to the BI-LEVEL position.
  2. OUTSIDE AIR button is in the ON position.
  3. A/C button is in the OFF position.
    • Air flows from the instrument panel outlets and floor outlets, slight air flow from the defrost outlets.
    • A/C is disengaged.
    • Outside air (ambient temperature) is delivered to passenger compartment.
    • Blower fan continues to operate at moderate speed.
    •  Air Delivery Improper

6
  1. Turn the HVAC mode control knob to the FLOOR position.
  2. Press the RECIRC button.
  3. A/C button is in the OFF position.
    • Air flows from the floor outlets with slight air flow from the defrost outlets.
    • A/C is disengaged.
    • Recirculated air is delivered to passenger compartment.
    • Blower fan continues to operate at moderate speed.
    •  Air Delivery Improper

7

Turn the HVAC mode control knob to the DEFOG position.
    • Air flows from the floor outlets and from the defrost outlets.
    • OUTSIDE AIR light illuminates allowing outside air into vehicle to help clear windows.
    • A/C is engaged.
    • Cold air is delivered to passenger compartment.
    • Blower fan continues to operate at moderate speed.
    •  Air Delivery Improper

8

Turn the HVAC mode control knob to the DEFROST position.
    • Air flows from the defrost outlets with slight air flow from the floor outlets.
    • OUTSIDE AIR light illuminates allowing outside air into vehicle to help clear windows.
    • A/C is engaged.
    • Cold air is delivered to passenger compartment.
    • Blower fan continues to operate at moderate speed.
    •  Air Delivery Improper

9

Rotate the blower knob from position 1 to position 5 and then back to position 1.

The blower motor speeds changes according to the blower switch position.

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.