For 1990-2009 cars

Step | Action | Yes | No
DEFINITION: Noise originating from the HVAC module.
1 | Were you sent here from Symptoms or another diagnostic table? | Go to Step 2 | Go to Symptoms - HVAC Systems - Manual in HVAC Systems-Manual
2 |

1. Start the engine.
2. Cycle through all of the following:

• | Blower motor speeds

• | HVAC modes

• | Temperature control settings

3. Determine the type of noise:

• | Scrape, pop

• | Tick/click, chirp or groaning

• | Air rush/whistle

Is a scrape or pop noise evident when selecting modes or temperature settings?

Go to Step 6

Go to Step 3

3 | Is a tick/click, chirping, groaning or scraping noise present, but decreases as blower motor speed is decreased? | Go to Step 6 | Go to Step 4
4 | Is an air rush/whistle noise evident in all modes but not all temperature settings? | Go to Step 6 | Go to Step 5
5 | Is an air rush/whistle noise evident only in defrost or floor mode? | Go to Step 6 | Go to Step 6
6 |

1. Remove the I/P center trim panel. Refer to Instrument Panel Center Trim Panel Replacement in Instrument Panel, Gages and Console.
2. Remove the center air outlet duct.

Is the action complete?

Go to Step 7

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7 |

1. Inspect the air flow doors for proper operation.
2. Inspect the ducts for obstructions or foreign materials.

Were any of these conditions found?

Go to Step 10

Go to Step 8

8 | Inspect the mode and temperature doors and seals for warping or cracking. Are the doors in normal condition? | Go to Step 11 | Go to Step 9
9 | Replace the appropriate door and/or seals. Is the repair complete? | Go to Step 11 | --
10 | Remove any obstructions or foreign material found. Is the action complete? | Go to Step 11 | --
11 |

1. Install the center air outlet duct.
2. Install the I/P center trim panel. Refer to Instrument Panel Center Trim Panel Replacement in Instrument Panel, Gages and Console.

Is the action complete?

Go to Step 12

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12 | Operate the system to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2