DEFINITION: Noise originating from the HVAC module.

Were you sent here from Symptoms or another diagnostic table?

Go to Step 2

Go to Symptoms - HVAC Systems - Manual in HVAC Systems - Manual or Symptoms - HVAC Systems - Automatic in HVAC Systems - Automatic

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

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

Is an air rush/whistle noise evident in all modes, but not all temperature settings?

Go to Step 6

Go to Step 5

Is an air rush/whistle noise evident only in defrost or floor mode?

Go to Step 6

Go to Step 1

Remove the instrument panel (I/P) trim pad. Refer to Instrument Panel Trim Pad Replacement in Instrument Panel, Gages, and Console.

Is the action complete?

Go to Step 7

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1. Inspect the mode valve assembly 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

Inspect the mode valve assembly, temperature door, and seals for warping or cracking.

Are the doors in normal condition?

Go to Step 11

Go to Step 9

Replace the appropriate door, mode valve assembly, or seals.

Is the repair complete?

Go to Step 11

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Remove any obstructions or foreign material found.

Is the action complete?

Go to Step 11

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Install the I/P trim pad. Refer to Instrument Panel Trim Pad Replacement in Instrument Panel, Gages, and Console.

Is the action complete?

Go to Step 12

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Operate the system to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2