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 - Manual

or

Symptoms - 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 location of noise:

•	Recirculation door

•	Temperature door

•	Mode valve

Is noise evident when selecting recirculation?

Go to Step 6

Go to Step 3

Is noise evident when selecting temperature?

Go to Step 6

Go to Step 4

Is noise evident when selecting mode ?

Go to Step 5

Go to Step 2

1. Remove HVAC module. Refer to HVAC Module Assembly Replacement .
2. Inspect mode valve for dust, dirt or debris.

Is dust, dirt or debris present?

Go to Step 11

Go to Step 12

Remove the HVAC module. Refer to HVAC Module Assembly Replacement .

Is action complete?

Go to Step 7

--

1. Inspect the air flow door 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 air flow door for warping or cracking.

Is air flow door in normal condition?

Go to Step 13

Go to Step 9

Replace air flow door .

Is repair complete?

Go to Step 13

--

Remove any obstructions or foreign material found.

Is action complete?

Go to Step 13

--

Vacuum and remove dust, dirt and debris.

Is action complete?

Go to Step 14

--

Replace the upper evaporator case. Refer to Air Conditioning Evaporator Core Replacement .

Is action complete?

Go to Step 14

--

Install HVAC Module. Refer to HVAC Module Assembly Replacement .

Is action complete?

Go to Step 14

--

Operate the system to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2