GM Service Manual Online
For 1990-2009 cars only

Tools Required

SA9216NE OTC Tool

Removal Procedure

Caution: Protect yourself by wearing safety glasses, earplugs, a respirator, gloves, and safety shoes while performing work on the vehicle.

Important: When applying cooling coil coating (P/N 12346390), use a National Institute of Occupational Safety and Health (NIOSH) approved acid gas/organic vapor respirator with chlorine dioxide cartridges (3M™ P/N 5103-small, 5203-medium, 5303-large), which are to be used with a pre-filter (P/N 5010) and retainer (P/N 501), or equivalents.


    Object Number: 878155  Size: SH
  1. Dry the evaporator by performing the following steps:
  2. 1.1. Adjust the temperature to full hot.
    1.2. Adjust the mode to heater only.
    1.3. Turn the RECIRC ON.
    1.4. Ensure the A/C button is OFF.
    1.5. Close all doors and windows.
    1.6. Start the engine and allow the engine to reach operating temperature.
    1.7. Once the engine reaches operating temperature, allow the blower motor to operate on HI blower for 5 minutes.

    Caution: Refer to Vehicle Lifting Caution in the Preface section.

  3. Raise the vehicle on a hoist.
  4. Check the HVAC module drain for blockage. If necessary, clear the drain hole with a soft blunt tool such as the eraser end of a pencil.
  5. Lower the vehicle from the hoist.
  6. Place a drain pan directly below the HVAC drain to collect disinfectant or cooling coil coating and rinse the water runoff.
  7. 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.
  8. Cover the interior of the vehicle to protect it from spray.
  9. 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 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.

    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.

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

  11. Object Number: 894220  Size: SH
  12. Remove the right side console extension.

  13. Object Number: 896491  Size: SH
  14. Remove the right side I/P lower dash insulator retainers.
  15. Pull the insulator rearward to detach the insulator from the forward insulator support.
  16. Remove the insulator support from the front of the dash studs by pulling rearward.

  17. Object Number: 897891  Size: SH
  18. Remove the right side heater duct assembly retainer and remove the duct.

  19. Object Number: 894362  Size: SH
  20. 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.
  21. Notice: To avoid cutting internal components, cut only inside raised bead area.

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

  22. 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.
  23. Notice: Use care when cleaning and removing debris around the evaporator as not to damage the fins.

  24. Carefully clean out any moisture or debris that may be inside the module.
  25. Put on rubber gloves, safety glasses, and NIOSH approved acid gas/organic vapor respirator.
  26. Using the cleaning gun, SA9216NE siphon-type parts cleaning spray gun capable of delivering 2 ounces per minute of liquid with shop air at 552-620 kPa (80-90 psi), insert the siphon hose into the container of cooling coil coating. Take care to place the bottle in a secure upright position to avoid spilling contents.
  27. Regulate shop air to 276-414 kPa (40-60 psi).
  28. Insert the nozzle tip of the spray gun so the spray pattern will be parallel to the evaporator face.
  29. Apply the 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.

  30. Object Number: 894363  Size: SH

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

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

Installation Procedure


    Object Number: 894354  Size: SH
  1. Install the evaporator core service door (P/N 22679783) to module and install the screws.
  2. Tighten
    Tighten the evaporator core service door-to-HVAC module fasteners to 1.0 N·m (9 lb in).


    Object Number: 897891  Size: SH
  3. Install the right side heater duct assembly and the retainer.
  4. Install the insulator support to front-of-dash studs by sliding the insulator forward.

  5. Object Number: 896491  Size: SH
  6. Install the right side I/P lower dash insulator and the retainers.

  7. Object Number: 894220  Size: SH
  8. Install the right side console extension.
  9. Allow the evaporator core to soak for 15 minutes.
  10. Important: The 5 minute drying time is an important step in curing the cooling coil coating to the evaporator.

  11. Dry the evaporator by performing the following steps.
  12. 7.1. Adjust the temperature to full hot.
    7.2. Adjust the mode to heater only.
    7.3. Turn the RECIRC ON.
    7.4. Ensure the A/C button is OFF.
    7.5. Open the windows 1/2 inch and close the doors.
    7.6. Start the engine and allow the engine to reach operating temperature.
    7.7. Allow the blower motor to operate on HI blower for 5 minutes once the engine reaches operating temperature.
  13. Properly dispose of the cooling coil coating runoff collected in the drain pan into a sanitary drain.
  14. Remove the protective coverings from the interior of the vehicle.