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Noise Diagnosis - HVAC Module

Noise Diagnosis - HVAC Module


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 - Automatic
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 instrument panel (I/P) carrier. Refer to Instrument Panel Tie Bar Replacement . Is the action complete? Go to Step 7 -
7

Inspect the air flow doors for proper operation.

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 carrier. Refer to Instrument Panel Tie Bar Replacement . Is the action complete? Go to Step 12 -
12
Operate the system in order to verify the repair. Did you find and correct the condition? System OK Go to Step 2