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
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 | Remove the I/P assembly. Refer to Instrument Panel Assembly Replacement. Is the action complete? | Go to Step 7 | --
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 | Install the I/P assembly. Refer to Instrument Panel Assembly Replacement . Is the action complete? | Go to Step 12 | --
12 | Operate the system to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2