GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 Park Avenue 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Cooling Insufficient - Air Conditioning (A/C) System

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. If the reply to the question is yes, then start the specified diagnostic at step 4.

Step

Action

Value(s)

Yes

No

1

Did you perform the HVAC Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check

2

Perform the air delivery and temperature control check. Refer to Air Delivery and Temperature Control Check .

Are the actuators operating within their specified ranges?

--

Go to Step 3

Go to Symptoms

3

IMPORTANT: Indicated outside air temperature must be above 16°C (60°F).

  1. Cover the sunload sensors.
  2. Start the engine.
  3. Fully open all panel outlets.
  4. Adjust driver side temperature to 16°C (60°F).
  5. Select PANEL mode.
  6. Set blower speed to maximum.
  7. Adjust passenger temperature control to neutral.
  8. Ensure that the VENT mode indicator is not illuminated.

Does the A/C compressor operate?

--

Go to Step 4

Go to HVAC Compressor Clutch Does Not Engage

4

Does the blower operate and provide sufficient airflow?

--

Go to Step 5

Go to Blower Motor Does Not Operate Properly

5

Perform the refrigerant system performance test. Refer to System Performance Test .

Are low and high side pressures within specification?

--

Go to Step 6

Go to VDOT Air Conditioning (A/C) System Diagnosis

6

Check right and left panel temperature sensors for proper installation. Refer to Panel Discharge Sensor Replacement - Left Side and Panel Discharge Sensor Replacement - Right Side .

Did you find and correct the condition?

--

Go to Step 19

Go to Step 7

7
  1. Start the engine.
  2. Fully open all panel outlets.
  3. Adjust driver side temperature to 24°C (75°F).
  4. Select PANEL mode.
  5. Set blower speed to illuminate 2 bars on the fan speed indicator.
  6. Adjust passenger temperature control to neutral.
  7. Inspect for airflow through the inside air temp sensor by placing a 5cm (2in) square piece of paper over the sensor air inlet.

Does the paper stay in place?

--

Go to Step 8

Go to Step 11

8
  1. Turn the engine OFF.
  2. Install a scan tool.
  3. Cover the sunload sensors.
  4. Start the engine.
  5. Adjust driver side temperature to 24°C (75°F).
  6. Adjust passenger temperature control to neutral.
  7. With a scan tool, observe the Right and Left Solar Sensor data parameters in the Heating and Air Conditioning Open/Short Data list.

Does the scan tool indicate that both the right and left solar sensor parameters are greater than the specified value?

230 Counts

Go to Step 9

Go to Step 14

9
  1. Uncover the sunload sensors.
  2. Direct the J 28428-E High Intensity Black Light at the right and then the left sunload sensor.

Do the counts change similarly and correspond to the proper sunload sensor?

--

Go to Step 10

Go to Step 14

10
  1. Install a thermometer as near as possible to the in-car, right and left panel temperature sensors.
  2. With a scan tool, observe the Inside Air Temp, Right and Left A/C Duct Temp data parameters in the Heating and Air Conditioning HVAC Sensors data list.

Does the scan tool indicate sensor temperatures near the thermometer temperatures within the specified range?

+3°C(5°F) to -3°C(-5°F)

Go to Too Warm in Car

Go to Step 12

11

Inspect for a blocked or disconnected aspiration hose.

Did you find and correct the condition?

--

Go to Step 19

--

12

Inspect for poor connections at the harness connector of the suspect temperature sensor. 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 19

Go to Step 13

13
  1. Turn OFF the ignition.
  2. Test the suspect temperature sensor resistance. Refer to Sensor Resistance Table .

Does the resistance measure near the specified value?

--

Go to Step 15

Go to Step 17

14

Inspect for poor connections at the harness connector of the suspect sunload sensor. 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 19

Go to Step 16

15

Inspect for poor connections at the harness connector of the heater and A/C programmer. 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 19

Go to Step 18

16

Replace the sunload sensor. Refer to Sun Load Sensor Replacement .

Did you complete the replacement?

--

Go to Step 19

--

17

Replace the temperature sensor. Refer to Panel Discharge Sensor Replacement - Left Side and Panel Discharge Sensor Replacement - Right Side .

Did you complete the replacement?

--

Go to Step 19

--

18

Replace the heater and A/C programmer. Refer to Programmer Replacement .

Did you complete the replacement?

--

Go to Step 19

--

19

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2