HVAC System Check. Pontiac Sun Runner - 4WD (Canada) 1998

For 1990-2009 cars

Step | Action | Normal Result(s) | Abnormal Result(s)*
--- | --- | --- | ---

1

• | Start the engine.

• | Move the blower speed selector switch from OFF to the following positions in the following order:

1. | LOW

2. | MEDIUM 1

3. | MEDIUM 2

4. | HIGH

5. | OFF

• | The blower motor speed increases as the blower speed selector switch is moved towards the HIGH position.

• | The blower motor speed decreases as the blower speed selector switch is moved towards the LOW position.

• | Blower Motor Operates at High Speed Only

• | Blower Motor Low Speed Inoperative

• | Blower Motor Inoperative Med-1

• | Blower Motor Inoperative Med-2

• | Blower Motor Inoperative at Any Speed

• | Blower Motor High Speed Inoperative

2

• | Engine idling until operating temperature is reached.

• | Move the mode control to the heat mode.

• | Move the temperature control to full heat.

• | Heated air is delivered to the passenger compartment.

• | Most of the heated air is delivered through the floor outlets with some air delivered to the windshield and side window outlets.

• | Heating Insufficient

• | Heat Excessive (Heater Mode)

• | Air Delivery Improper

• | Heat Excessive (Vent Mode)

• | Noise Diagnosis

• | High or Low Temperature Control Effort

3

• | Engine still idling.

• | Move the mode control to the defrost mode.

• | Move the temperature control to full heat.

• | Heated air is delivered to the passenger compartment.

• | Most of the heated air is delivered to the windshield with some air delivered to the side window outlets.

• | Defrosting Insufficient

• | Heat Excessive (Heater Mode)

• | Air Delivery Improper

• | Heat Excessive (Vent Mode)

• | Noise Diagnosis

• | High or Low Temperature Control Effort

4

• | Engine still idling.

• | Move the blower speed selector switch to any position except OFF.

• | Move the temperature control to the full cold position.

• | Press the A/C switch to ON.

• | The blower motor runs.

• | The condenser fan motor runs.

• | The A/C compressor clutch engages.

• | Cold air is delivered to the passenger compartment.

• | The compressor stops running if the engine coolant temperature exceeds 113°C (235°F).

• | The compressor and the condenser fan motor stop running if any of the following conditions are met:

• | The A/C system pressure drops below 193 kPa (28 psi)

• | The A/C system pressure exceeds 3137 kPa (455 psi)

• | The evaporator core temperature drops below 0°C (32°F)

• | HVAC Compressor Clutch Does Not Engage

• | Condenser Fan Inoperative

• | Odor Diagnosis

• | TXV Air Conditioning (A/C) System Diagnosis

• | Noise Diagnosis

• | TXV Air Conditioning (A/C) System Diagnosis

5

• | Press the A/C switch to OFF.

• | Move the blower speed selector switch to OFF.

• | The blower motor stops.

• | The A/C compressor clutch disengages.

• | The condenser fan motor stops once the engine coolant temperature drops below 113°C (235°F).

• | Blower Motor Always On

| HVAC Compressor Clutch Does Not Disengage

• | Condenser Fan Always On

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