GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1999 🢒 Firefly (Canada) 🢒 Engine 🢒 Engine Controls - 1.3L 🢒 HVAC System Check

Step

Action

Normal Results

Abnormal Results*

1
  1. Start the engine.
  2. Move the blower speed selector switch to the following positions in the following order:
    3. 2.1. LOW
    2.2. MEDIUM 1
    2.3. MEDIUM 2
    2.4. HIGH
    2.5. OFF

The blower motor speed increases at each speed level when you turn the blower speed selector switch towards the HIGH position.
    •  Blower Motor Always On

2
    • Run the engine at idle until the operating temperature is reached.
    • Move the blower speed selector switch to any position except OFF.
    • Move the mode control to the VENT position.
    • Move the temperature control to the coldest position.
    • The blower motor operates at the selected speed.
    • Ambient air enters the passenger compartment through the instrument panel outlets.
    • Heating Insufficient
    • Heat Excessive (Vent Mode)
    • Heat Excessive (Heat Mode)
    • High or Low Temperature Control Effort
    • Air Delivery Improper

3
    • Move the blower speed selector switch to any position except OFF.
    • Move the mode control to the HEAT position.
    • Move the temperature control to the hottest position.
    • The blower motor operates at the selected speed.
    • Heated air enters the passenger compartment.
    • Most of the heated air comes through the floor outlets. Some air comes through the windshield outlets and through the side window outlets.
    • Heating Insufficient
    • Heat Excessive (Vent Mode)
    • Heat Excessive (Heat Mode)
    • High or Low Temperature Control Effort
    • Air Delivery Improper

4
    • Move the blower speed selector switch to any position except OFF.
    • Move the mode control to the DEFROST position.
    • Move the temperature control to the hottest position.
    • The blower motor operates at the selected speed.
    • Heated air enters the passenger compartment.
    • Most of the heated air goes to the windshield. Some air goes through the side window outlets and through the floor outlets.
    • Heating Insufficient
    • Heat Excessive (Vent Mode)
    • Heat Excessive (Heat Mode)
    • High or Low Temperature Control Effort
    • Air Delivery Improper

5
  1. Move the blower speed selector switch to any position except the OFF position.
  2. Move the temperature control to the coldest position.
  3. Press the air conditioning (A/C) switch to the ON position.
    • The blower motor operates at the selected speed.
    • The A/C compressor clutch engages.
    • The A/C condenser fan motor operates.
    • Cold air enters the passenger compartment.
    • The A/C compressor control module may cycle the A/C compressor clutch and the A/C condenser fan motor ON and OFF.
    • TXV A/C System Diagnosis (Insufficient Cooling)
    • TXV A/C System Diagnosis (Reference Table)
    • Odor Diagnosis

6

Turn the A/C switch to the OFF position.
    • The A/C compressor clutch disengages.
    • The fan motor of the A/C condenser stops operating.

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