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 around the auxiliary HVAC module.

Did you find any of these conditions?

Go to Step 7

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 auxiliary blower motor impeller and body for damage.

Did you find any of these conditions?

Go to Step 5

Go to Step 6

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

Did you replace the auxiliary HVAC blower motor?

Go to Step 8

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Inspect the auxiliary HVAC module case for damage or foreign materials.

Did you find any of these conditions?

Go to Step 7

Go to Symptoms - HVAC Systems - Automatic

Repair or replace any faulty components, remove any foreign materials from the auxiliary HVAC module case.

Did you find and correct the condition?

Go to Step 8

Go to Step 3

Operate the system under various conditions.

Did you find and correct the condition?

System OK

Go to Symptoms - HVAC Systems - Automatic