GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1998 🢒 Park Avenue 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Functional Check

In order to effectively diagnose the electronic air conditioning system condition, utilize the diagnostic procedure outline with each step performed in the order presented.

Perform the climate control functional test with the engine warm and running at idle. The temperature outside the vehicle should be at least 6 degrees Celsius, 43 degrees  Fahrenheit.

  1. If the engine was recently running , a purge delay of approximately 20 seconds may occur before a mode selection becomes active. This delay is normal and prevents windshield fogging.
  2. In order to prevent the windshield frosting during a cold startup and cool outside temperatures the system delays the operation modes until the engine is warm (except when selecting defrost).

Step

Action

Normal Result(s)

1

Press the FRONT button.
    • The FRONT button LED lights
    • The WINDSHIELD and the windshield's air distribution indicator arrow appear.
    • The SET TEMP displays.
    • The air flows from the defroster outlets.
    • After 10 seconds, the SET TEMP display switches to the outside air temperature.

2

Press the AIR FLOW button.

The control head displays the system status for 10 seconds and then returns to EXT TEMP.

--

3
  1. Press and hold the bottom of the AIR FLOW button.
  2. Set the air distribution to FLOOR and WINDSHIELD.
    • The WINDSHIELD and the FLOOR with the air distribution arrows appear.
    • The SET TEMP displays.
    • The air flows from the windshield defroster and the heater outlets.
    • After 10 seconds the SET TEMP display changes to EXT TEMP. The rest of the display remains the same.

4
  1. Press and hold the top of the AIR FLOW button.
  2. Set the air distribution to MID.
    • The MID and the MID's distribution arrows (up and down) appear.
    • The SET TEMP displays.
    • The air flows from the IP outlets.
    • After 10 seconds the SET TEMP display changes to EXT TEMP. The rest of the display remains the same.

5

Using the AIR FLOW button, set the air distribution to FLOOR and MID.
    • The MID and the MID's up arrow. The FLOOR and the FLOOR'S distribution arrow appear.
    • The SET TEMP displays
    • The air flows from the I/P and the heater outlets.
    • After 10 seconds the SET TEMP display changes to EXT TEMP. The rest of the display remains the same.

6

Using the AIR FLOW button, set the air distribution to FLOOR.
    • The FLOOR and the FLOOR'S distribution arrow appear.
    • The SET TEMP displays.
    • The air flows from the heater outlets.
    • After 10 seconds the SET TEMP display changes to EXT TEMP. The rest of the display remains the same.

10

Press the RECIRC button.
    • The RECIRC button LED lights.
    • The blower motor air noise changes as the system goes from the outside air to the RECIRC modes.

11

Press the VENT button.
    • The VENT button LED lights.
    • The RECIRC button LED goes out
    • The RECIRC door closes
    • The A/C compressor turns off.
    • The VENT and the RECIRC modes do not operate simultaneously.

12

Press the REAR button.
    • The REAR button LED lights.
    • The defogger grid warms.
    • The rear button goes off after the DEFOGGER times out, or after the REAR button is pushed again.

13
  1. Set the AIR FLOW to MID.
  2. Set the PASSENGER CONTROL WARM or COOL dial.
    • The orange center LED bar lights. The WARMER and the COOLER words light.
    • The orange LED indicates no temperature off set.

14

Adjust the PASSENGER CONTROL to WARM then COOL.
    • The segment bars rise and fall with the WARM and the COOL buttons.
    • The AIR TEMPERATURE OFF SET from the right to the left I/P outlets slowly rises and falls with the WARM and the COOL selections.

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