Air Conditioning (A/C) Odor Treatment

Special Tool(s)

Flexible Applicator Tool 258-00005

 WARNING: Carry out this procedure in a well-ventilated area with all vehicle windows and doors opened. Carefully read cautionary information on product label. For emergency medical information, seek medical advice. On Ford/Motorcraft products in the USA or Canada call: 1-800-959-3673. For additional information, consult the product Material Safety Data Sheet (MSDS), if available. Failure to follow these instructions may result in serious personal injury.

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 odor treatment is required, the source and the circumstances under which the odor occurs must be determined.

NOTE: 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.

NOTE: 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.

NOTE: 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.

NOTE: 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 below.

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 following chart for examples.
   
   

   Odor Source	Odor Description
   Chemical Odors
   Coolant	Sweet smell
   Fuel	Gasoline or diesel fuel smell
   Oil	Oil type or burning smell
   Power Steering Fluid	Oil type or burning smell
   Transmission Fluid	Oil type or burning smell
   Washer Fluid	Alcohol type smell
   Gear Lube	Garlic/sulfur smell
   Refrigerant Oil	Ether type smell
   Carpet/trim Adhesives	Fishy, urine or sweet smell
   Evaporator Core Coating	Wet cement type smell
   Environmental Odors
   Exhaust	Exhaust, fuel or burning type smell
   Industrial Pollutants	Various smells
   Dust	Musty, mildew or wet cement type smell
   Pollen	Sweet smell
   Tobacco	Burning, tar smell
   Human and Other Interior Generated Odors
   Body Secretions	Body odor
   Perfuming Agents	Sweet or fragrance smell
   Clothing	Musty, mildew or body odors
   Food/Beverage	Sweet, musty, mildew or fishy smell
   Microbiological Odors
   Microbiological Odors Occurring Inside of A/C System	Musty, mildew smell lasting about 30 seconds after A/C is turned on
   Microbiological Odors Occurring Outside of A/C System	Musty, mildew smell lasting indefinitely and possibly more pronounced when using recirculated air

   
   

2. Identify the source of the odor.
   • Check the evaporator core drain tube for restriction.
   • Check the passenger and driver side carpet for moisture. If moisture is found, A/C odor treatment is not necessary. Diagnose for a water leak as needed.
   • Check the blower motor and blower motor cover (if equipped) for moisture resulting from water bypassing the cowl baffling system. If moisture is found, A/C odor treatment is not necessary. Diagnose for a water leak as needed.
   • 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 and doors.

4. Make sure that the A/C is off.

5. Set the following.
   • Select PANEL mode (A/C off).
   • Adjust the temperature setting to full warm.
   • Adjust the blower motor speed to HI.

6. Run the engine for 25 minutes to dry out the A/C system.

7. Turn the ignition OFF.

8. Remove the blower motor.

9. 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).

10. NOTICE: 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 Flexible Applicator Tool.

11. Insert the nozzle into the evaporator housing and direct the spray toward the evaporator core face. Spray the entire evaporator core face until empty.

12. Install the blower motor and blower motor resistor (if equipped) or blower motor speed control (if equipped).

13. Repeat Steps 4 through 6 to cure the evaporator core coating.