Odor from A/C at Vehicle Start-Up

A musty odor from A/C system, most noticeable at vehicle start-up.

An unpleasant (musty) odor from A/C outlets at vehicle start-up can be the result of microbial growth on the evaporator core.

Remove any debris from the evaporator case and apply cooling coil coating according to the procedures in this bulletin.

Before starting procedure, obtain the following equipment and supplies.

1. Dry evaporator by:

•	Adjusting temperature to full hot

•	Adjusting mode to heater only

•	Turning RECIRC On

•	Making sure A/C button is Off

•	Close all doors and windows

•	Start engine and allow to reach operating temperature

•	Once engine reaches operating temperature, allow blower motor to operate in HI blower for 5 minutes.

Caution: Make sure the vehicle is properly supported and squarely positioned on the hoist. To help avoid personal injury, provide additional support to the opposite end of the vehicle that components are removed from.

2. Raise the vehicle on a hoist.



3. Check the HVAC module drain for blockage. If necessary, clear drain hole with a soft blunt tool such as a pencil eraser.
4. Lower the vehicle from the hoist.
5. Place a drain pan directly below the HVAC drain to collect disinfectant or cooling coil coating and rinse water runoff.
6. Open all doors and windows in the vehicle and position the pedestal fan so that it provides cross ventilation through the vehicle during the cleaning/coating procedure.
7. Cover the interior of the vehicle with suitable protective coverings to protect the surfaces from overspray.

Caution: The following procedure should only be performed on a cold vehicle. It has been demonstrated that irritating vapors will be formed in the engine compartment if the cooling coil coating coming out of the drain outlet contacts the hot engine components. Cooling coil coating can cause substantial, but temporary eye injury. Do not get cooling coil coating in eyes or on clothing. Wash thoroughly with soap and water after handling.

Caution: First Aid: If cooling coil coating gets into eyes, hold eyelids open and flush with a steady, gentle stream of water for 15 minutes. Obtain medical attention if irritation persists.

8. Allow the vehicle to cool down before performing cooling coil coating procedure.



9. Remove the right side of console extension.



10. Remove right side I/P lower dash insulator retainers.
11. Pull the insulator rearward to detach from the forward insulator support.
12. Remove the insulator support from the front of the dash studs by pulling rearward.



13. Remove the right side heater duct assembly retainer and remove the duct.



14. Locate the evaporator access door location on the right side of the module. The entire area inside the raised lip needs to be cut out.

Caution: To avoid cutting internal components, cut only inside the raised bead area.

Notice: Do not cut through or damage raised bead, this bead will be used as a sealing surface when completing procedure.

15. Using a sharp utility knife, cut through the module wall, following the inside of the raised bead as a guide. Several passes may be necessary to do this.

Notice: Use care when cleaning and removing debris around the evaporator as not to damage the fins.

16. Carefully clean out any moisture or debris that may be inside the module.
17. Put on rubber gloves, safety glasses, and NIOSH approved acid gas/organic vapor respirator.
18. Using cleaning gun, OTC Tool SA9216NE (or equivalent siphon-type parts cleaning spray gun capable of delivering 2 ounces per minute of liquid with ship air at 552-620 kPa [80-90 psi]), insert siphon hose into container of cooling coil coating. Take care to place the bottle in a secure upright position to avoid spilling contents.
19. Regulate the shop air to 276-414 kPa (40-60 psi).
20. Insert the nozzle tip of the spray gun so the spray pattern will be parallel to the evaporator face.
21. Apply cooling coil coating using short bursts and rotating the nozzle tip up and down. This will allow for an even distribution and to ensure full coverage of the evaporator.

Notice: Proper sealing is important to prevent condensation from leaking into the passenger compartment.




22. Apply provided sealant to service door at tongue and groove location as shown.



23. Install the evaporator core service door (P/N 22679783) to module and install screws.

Tightening
Tighten the Evaporator Core Service Door-to-HVAC Module Fasteners to 1 N·m (9 lb in).




24. Install the right side heater duct assembly and retainer.
25. Install the insulator support to front-of-dash studs by sliding forward.



26. Install the right side I/P lower dash insulator and retainers.



27. Install the right side console extension.
28. Allow the evaporator core to soak for 15 minutes.

Important: The 5 minute drying time is an important step in curing the cooling coil coating to the evaporator.

29. Dry evaporator by:

•	Adjusting temperature to full hot

•	Adjusting mode to heater only

•	Turning RECIRC On

•	Making sure A/C button is Off

•	Open windows 1/2 in. and close doors

•	Start engine and allow to reach operating temperature

•	Allow blower motor to operate on HI blower for 5 minutes once engine reaches operating temperature.

30. Properly dispose of cooling coil coating runoff collected in drain pan into a sanitary drain.
31. Remove the protective coverings from the interior of the vehicle.

To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System for D3319 (Core, Evaporator - Clean and Disinfect), or if another procedure is performed, refer to the appropriate Electronic Labor Time Guide for the correct Labor Operation Code and Time.