Check a VIN

April 16, 2018 Service bulletin

A musty/mildew type odor may come from the vents when the air conditioning (A/C) system is operating

Mazda technical service bulletin 07-002-18-3432 for 2004-2018 Mazda MAZDA3, 1998-2002 Mazda 626 and 2013-2018 Mazda CX-5 and others.

Bulletin number
07-002-18-3432
Component
Equipment: appliance: air conditioner
Summary
A musty/mildew type odor may come from the vents when the air conditioning (A/C) system is operating. It is most noticeable when the A/C is first turned ON. This odor is the result of mold growth in the A/Cevaporator/cooling unit which is caused by condensation, dust, and pollen within the cooling unit. This condition is usually worse during high humidity conditions. "Mazda Air Cooling Coil Coating" is available to encapsulate the mold to reduce odors. If the product is properly applied, it can effectively reduce the musty/mildew odor for up to three years. NOTE: See parts information for Mazda Air Cooling Coil Coating and Kit part numbers. This treatment provides a durable coating that will aid to prevent biological reactions that lead to odorconcerns. It is applied to the evaporator in a misted form that is introduced by way of the cabin air filter, the re-circulate door, the blower motor resistor access, or the blower motor air intake. Proper application requires the evaporator surface to be: Relatively clean and free of leaves, dust build-up and debris. Thoroughly dried, and the product cured onto it after application. NOTE: Keep the cooling unit dry by leaving the blower fan ON (at least on low), even if the A/C is not being used. In low humidity (dry) conditions, keep the ventilation system in the "FRESH" mode all the time, or as much as possible. In high humidity conditions, or if the air has a lot of dust or pollen, keep the system in the "RECIRCULATION" mode. A few minutes before reaching a destination, turn the A/C OFF, but leave the blower fan ON. This stops the accumulation of condensation on the evaporator/cooling unit, and it helps dry the inside of the cooling unit. A/C odor is not unique to Mazda vehicles as it will occur in other makes and models. To minimize A/C odor, suggest the following to the customers.

Vehicles covered

VIN decoder

See the problems and recalls for an exact car

Buying a used Mazda MAZDA3?

Check the exact car before you pay: accidents, salvage or flood titles, odometer readings and previous owners.

Check its history