Air Conditioning (A/C) Odor Treatment

AIR CONDITIONING (A/C) ODOR TREATMENT

Special Tool(s):

Special Tool(s)

A/C Odor Treatment

WARNING:
- Avoid contact with eyes and skin. Contact with eyes and skin will cause irritation. Wear chemical goggles when using the A/C cooling coil coating.
- This procedure should only be carried out in well ventilated areas. Open all windows and doors of the vehicle. Leave doors and windows open during the entire procedure. Avoid breathing vapors.
- Read all instructions and warnings packaged with the A/C cooling coil coating.

NOTE:
- There are typically 4 types of objectionable odors found in a vehicle:
- Chemical odors
- Environmental odors
- Human and other interior-generated odors
- Microbiological odors

Before determining that A/C order treatment is required, the source and the circumstances under which the odor occurs must be determined.

- Chemical odors are usually constant regardless of the climate control system setting although they may be enhanced by A/C operation. Most chemical odors are caused by fluid leaks or incorrectly cured adhesives. Chemical odors can be eliminated by repairing the leaking component and removing any residue.
- Environmental odors usually occur for a short time and diminish after the vehicle passes through the affected area. These odors are typically only detected when the vehicle windows are open, or when the climate control system is operating in a mode that allows for fresh air. Environmental odors cannot be eliminated because they are external in source, but they may be minimized by switching to a climate control setting that uses recirculated air.
- Human and other interior-generated odors occur while the source is present and may linger for a short time after. These odors may be more noticeable during A/C operation. Human odors may be eliminated by removing the source and cleaning the affected area.
- Microbiological odors, if in the A/C system, usually last for about 30 seconds after the system is turned on. They will be detected while the A/C is turned on and using either outside or recirculated air. Microbiological odors that occur in areas other than the A/C system (for example, water in doors or wet carpeting) may last indefinitely and will be more intense when recirculated air is used. Microbiological odors will not be present at temperatures at or below 10°C (50°F).

Microbiological odors can be eliminated by removing the source and treating the affected area. Standing water must be allowed to drain and dry out. A/C systems may be treated by using A/C cooling coil coating as described in the service procedure.

Microbiological odors result from microbial growth supported by warm temperatures and moisture. Microbiological odors are described as musty/mildew type smells and may occur on/in:
- foam seals.
- rubber seals.
- adhesives.
- standing water.
- water soaked carpet/trim.







1. Identify the type of odor present in the vehicle. Do not proceed with A/C odor treatment if the odor source is found to be outside of the A/C system. Refer to the chart for examples.
2. Identify the source of the odor.
- Check the passenger and driver side carpet for moisture. Continue diagnosis if moisture is found.
- Check the blower motor and blower motor cover (if equipped) for moisture resulting from water bypassing the cowl baffling system. Continue diagnosis if moisture is present.
- Check the evaporator core drain tube for restriction.
- Check the cowl top panel and air inlet screen for standing water or foreign material. If possible, remove any standing water and clean the air inlet screen using a wet/dry vacuum.

3. Open all vehicle windows.
4. Disconnect the low-side A/C pressure switch (cycling or low-charge protection) electrical connector.
5. Remove the evaporator air discharge temperature sensor (if equipped).
6. Set the following.
- Enable the A/C using fresh air inlet.
- Adjust the temperature setting to full warm.
- Adjust the blower motor speed to HI.

7. Run the engine for 25 minutes to dry out the A/C system.
8. Turn the ignition OFF.
9. Remove the blower motor.

10. NOTE: Blower motor speed controls that are mounted outside of the evaporator core housing and not exposed to the blower motor airflow do not need to be removed.

Remove the blower motor resistor (if equipped) or blower motor speed control (if equipped and exposed to the inside of the evaporator core housing).

11. CAUTION: To avoid damage to the vehicle interior, do not spill or spray this product on any interior surface.

Add one full bottle of A/C cooling coil coating to the applicator or sprayer.

12. Insert the nozzle into the evaporator housing and direct the spray toward the evaporator core face. Spray the entire evaporator core face until empty.
13. Install the blower motor and blower motor resistor (if equipped) or blower motor speed control (if equipped).
14. Install the evaporator air discharge temperature sensor (if equipped),
15. Repeat Steps 6 through 8 to cure the evaporator core coating.
16. Connect the low-side A/C pressure switch (cycling or low-charge protection) electrical connector.