Step

Action

Yes

No

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 - 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 6

Remove the instrument panel (I/P) assembly. Refer to Instrument Panel Assembly 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 and temperature doors and seals for warping or cracking.

Are the mode valve assembly and temperature doors in normal condition?

Go to Step 11

Go to Step 9

Replace the appropriate component.

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

--

Install the I/P assembly. Refer to Instrument Panel Assembly Replacement in Instrument Panel, Gages and Console.

Is the action complete?

Go to Step 12

--

Operate the system to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2