Were you sent here from Symptoms or another diagnostic table?

Go to Step 2

Go to Symptoms - HVAC Systems - Automatic

Inspect the Auxiliary HVAC module for correct fitting and or loose components in and around the HVAC module.

Did you find any of these conditions?

Go to Step 5

Go to Step 3

1. Sit inside the vehicle.
2. Close the vehicle doors and windows.
3. Ignition ON, engine OFF.
4. Activate the Auxiliary HVAC module.
5. Cycle through all of the fan speeds:

Is noise present from the Auxiliary HVAC module?

Go to Step 4

Go to Symptoms - HVAC Systems - Automatic

1. Remove the auxiliary HVAC blower motor. Refer to Auxiliary Blower Motor Replacement .
2. Inspect the interior of the auxiliary HVAC module case and body for damage and or foreign materials, inspect the evaporator for correct mounting.

Did you find any of these conditions?

Go to Step 5

Go to Step 6

Secure or replace any faulty component.

Did you repair or replace any faulty component?

Go to Step 9

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Inspect the blower motor impeller and body for damage.

Did you find any of these conditions?

Go to Step 7

Go to Symptoms - HVAC Systems - Automatic

Replace the auxiliary HVAC blower motor. Refer to Auxiliary Blower Motor Replacement .

Did you find and correct the condition?

Go to Step 8

Go to Symptoms - HVAC Systems - Automatic

Replace the auxiliary HVAC module. Refer to Auxiliary HVAC Module Replacement .

Go to Step 9

Go to Symptoms - HVAC Systems - Automatic

Operate the system under various conditions.

Did you find and correct the condition?

System OK

Go to Step 3