GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2002 🢒 Sunfire 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Too Hot in Vehicle

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This tests for A/C compressor engagement. Ambient air temperature must be above 3°C (38°F) for the compressor to engage.

    2.

  2. This tests for the blower motor functionality.

    3.

  3. This tests if the A/C compressor function is inoperative.

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

DEFINITION: The temperature cannot be adjusted, or the cooling is insufficient during A/C operation.

1

Did you perform the HVAC Diagnostics System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Manual

2

Important: The ambient air temperature must be above 3°C (38°F).

  1. Turn OFF the ignition.
  2. Inspect the A/C compressor for free rotation operation. Refer to Symptoms - HVAC Systems - Manual .
  3. Start the engine.
  4. Place the mode switch in Recirc or Defrost.
  5. Place the blower motor switch in the MAX position.
  6. Place the air temperature switch in the coldest position.

Does the A/C compressor operate?

Go to Step 3

Go to HVAC Compressor Clutch Does Not Engage

3

  1. Turn ON the ignition, with the engine OFF.
  2. Place the mode switch in any position except OFF.
  3. Place the blower switch in each speed position.

Does the blower motor operate in any of the speed positions?

Go to Step 4

Go to Blower Motor Inoperative

4

Does the blower motor operate at the desired speeds?

Go to Step 5

Go to Blower Motor Malfunction

5
  1. Start the engine.
  2. Place the blower motor switch in the maximum speed position.
  3. Place the mode switch in the recirculation position.

Does the recirculation door move to the recirculation position?

Go to Step 6

Go to Vacuum Control System Diagnostic

6

When the A/C is ON, does the customer concern occur?

Go to Step 7

Go to Step 8

7

Perform the refrigerant system performance test. Refer to Air Conditioning (A/C) System Performance Test in Heating, Ventilation and Air Conditioning.

Did you find and correct the condition?

Go to Step 11

Go to Step 8

8

Inspect the air temperature door and linkage for the following conditions:

    • Broken or binding linkages or air temperature door
    • An obstruction that prevents the air temperature door from operating within its full range of motion
    • Missing seals to the air temperature door
    • Misaligned seals to the air temperature door

Did you find and correct the condition?

Go to Step 11

Go to Step 9

9

Inspect for poor connections at the harness connector of the HVAC control assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step  10

10

Replace the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement .

Did you complete the replacement?

Go to Step 11

--

11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2