A/C - Musty/Mildew Type Odors
07-002/032001-2003 TRIBUTE
MUSTY / MILDEW ODOR FROM CLIMATE CONTROL SYSTEM
APPLICABLE MODEL(S)/VINS
2001 - 2003 Tribute
DESCRIPTION
Some vehicles may exhibit a musty and/or mildew-type odor coming from the climate control system. This odor may be caused by mildew-type fungi in the A/C evaporator. It is most noticeable when the A/C is first turned on.
To help reduce odors:
^ Apply Mazda Air Cooling Coil Coating to the A/C system, which encapsulates the mildew.
^ Install air inlet vacuum motor bleed valve, which operates the recirculation/fresh air door to default to fresh mode when the vehicle is parked to dry out the evaporator core.
Customers having this concern should have their vehicles serviced using the following repair procedure.
REPAIR PROCEDURE
1. Verify customer concern.
2. Try to reasonably rule out any other source for the odor.
^ Check the carpet on the passenger side for signs of being wet. Continue diagnosis if water is found on carpet and repair as needed.
^ Check the blower motor and the cover for signs of moisture. This may be a result of water bypassing the cowl baffling system that prevents rain intrusion.
3. Remove the engine side fasteners for the plenum cover. This will allow access to the cowl top panel-water RH.
a. Remove and inspect the air inlet screen.
b. Use a shop vacuum if there is debris present.
Note:
This debris may work its way in to the evaporator case and act as food for the microbes to grow.
c. Re-install the cowl components.
4. Check to see that the evaporator drain tube (or hose) is not plugged or restricted by debris. Clear anything that may be obstructing the drainage of water.
5. Disconnect A/C cycling switch electrical connector.
6. Start engine.
WARNING:
Running the engine inside an enclosed area, such as garage, is dangerous. Exhaust gas, which contains poisonous carbon monoxide, could easily enter the cabin. Loss of consciousness or even death could occur. Don't run the engine when inside an enclosed area.
7. Open vehicle windows.
8. Set the following:
^ Function selector switch in the Max A/C mode
^ Temperature at full heat
^ Blower at high speed
^ Engine running at normal operating temperature
9. Run engine in this condition for twenty-five minutes. This will dry out the system.
10. Turn ignition off.
11. Disconnect and remove the blower motor and blower motor resistor according to Workshop Manual (section 07-40 CONTROL SYSTEM - BLOWER MOTOR) (This provides ease of access to the evaporator core and eliminates the possibility of contaminating the blower motor and/or blower motor resistor with Mazda A/C Cooling Coil Coating.)
12. Shake the bottle of Mazda A/C cooling coil coating well (P/N 0000-77-570K-01) and attach it to applicator.
NOTE:
To avoid any possible damage, do not spill or spray this product on any interior surface (e.g. instrument panel) or material (e.g. carpeting).
13. Connect applicator to compressed air. For effective treatment, use the full four (4) fluid ounces on one vehicle application.
14. Insert applicator in opening of evaporator case and directly spray toward face of the evaporator core. Spray until bottle is empty, ensuring the entire core is coated.
15. Re-install blower motor resistor and blower motor immediately.
16. Repeat steps 7-10 to cure product.
17. Re-connect the A/C cycling switch connector.
AIR INLET VACUUM MOTOR BLEED VALVE TEE INSTALLATION
18. Remove the front passenger-side air bag according to Workshop Manual (section 08-10) PASSENGER AIR BAG MODULE.
19. Disconnect vacuum line at air inlet door vacuum motor.
20. Install bleed valve tee (P/N EC01-61-2E0) into line 90 degree connector, and attach vacuum line with the vacuum bleed tee to air inlet door vacuum motor according to Workshop Manual (section 07-40) VACUUM CONTROL MOTOR - OUTSIDE AIR INLET.
21. Re-install the front passenger-side air bag according to Workshop Manual (section 08-10) PASSENGER AIR BAG MODULE.
22. Verify repair.
PART(S) INFORMATION
WARRANTY INFORMATION
NOTE:
This information applies to verified customer complaints on vehicles covered under normal warranty. Refer to the SRT microfiche for warranty term information.