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Home >> Cadillac >> 2021 >> CT4 Sport, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 230 (Heating, Ventilation, And Air Conditioning - Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> Noise Diagnosis - HVAC Module

Noise Diagnosis - HVAC Module

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
Step Action Yes No
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 12 
6 Remove the instrument panel carrier. Instrument Panel Carrier Replacement (without Head Up Display) , or Instrument Panel Carrier Replacement (with Head Up Display)
Is the action complete?
Go to Step 7  -
7
  1. Remove the actuators.
  2. Inspect the air flow doors for proper operation.
  3. 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 instrument panel carrier. Instrument Panel Carrier Replacement (without Head Up Display) , or Instrument Panel Carrier Replacement (with Head Up Display)
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