GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2003 🢒 Bonneville 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Air Delivery Improper

Diagnostic Aids

Recirc will only operate for approximately 10 minutes when selected. After 10 minutes the recirc door switches to the outside air position. The tone of the blower and the velocity of the air speed may be noticeably different when the recirc actuator switches positions. This is a normal condition. If excessive air speed change is noticed inspect the cabin air filter for contamination or blockage.

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: Air does not flow correctly from the air distribution outlets.

1

Did you perform the HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Automatic

2
  1. Install a scan tool.
  2. With a scan tool, perform the Recalibrate all Motors command in Instrument Panel Module Special Functions.
  3. With a scan tool, observe the current DTC list in instrument panel integration module (IPM).

Does the scan tool display any DTCs?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

Place the blower motor 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 speed in each speed position?

Go to Step 5

Go to Blower Motor Malfunction

5
  1. Place the blower motor switch in the maximum speed position.
  2. Place the mode switch in the bi-level position.
  3. Alternately place the recirculation switch in the outside air and recirculation positions.

Does the recirculation door move from the recirculation position to the outside air position?

Go to Step 6

Go to Air Recirculation Malfunction

6
  1. Turn ON the ignition, with the engine OFF.
  2. Turn OFF the HVAC controls.

Is the blower motor OFF?

Go to Step 7

Go to Blower Motor Always On

7

Place the mode switch in each position.

Does the display on the HVAC control module respond correctly to changes in mode selection?

Go to Step 8

Go to Step 16

8

Place the mode switch in each position.

Does the air flow from the correct air distribution outlets in each mode position?

Go Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 9

9
  1. With a scan tool, observe the Htr./Def./A/C Dr. Commanded parameter in the Instrument Panel Module data list.
  2. Place the mode switch in each position.

Does the scan tool indicate that the Htr./Def./A/C Dr. Commanded parameter changes for each change in selected mode position?

Go to Step 10

Go to Step 17

10

Test the ignition 3 voltage circuit for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 11

11

Test the low reference circuit of the mode actuator for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 12

12

Test the 5 volt reference circuit of the mode actuator for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 13

13

Inspect the air delivery system for the following conditions:

    • A dirty HVAC filter, if applicable
    • An obstruction to the air flow
    • Air leaks
    • Misaligned air ducts

Did you find and correct the condition?

Go to Step 21

Go to Step 14

14

Inspect the mode door and the mode actuator for the following conditions:

    • Misaligned actuator door
         Refer to Mode Actuator Replacement .
    • Broken or binding linkages or mode door
    • Obstruction that prevents the mode actuator from operating within its full range of motion
    • Missing seals to the mode door
    • Misaligned seals to the mode door

Did you find and correct the condition?

Go to Step 21

Go to Step 15

15

Inspect for poor connections at the harness connector of the mode actuator. 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 21

Go to Step 18

16

Inspect for poor connections at the harness connector of the HVAC control module. 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 21

Go to Step 19

17

Inspect for poor connections at the harness connector of the IPM. 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 21

Go to Step 20

18

Replace the mode actuator. Refer to Mode Actuator Replacement .

Did you complete the replacement?

Go to Step 21

--

19

Replace the HVAC control module. Refer to HVAC Control Module Replacement .

Did you complete the replacement?

Go to Step 21

--

20

Important: Perform the recalibration procedure for the instrument panel IPM.

Replace the IPM. Refer to Instrument Panel Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 21

--

21

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2