For 1990-2009 cars

The air conditioning system may emit odors primarily at startup in hot or humid climates. This odor may be the result of one of the following conditions:

• | Debris in the heater A/C module

• | Growth of mold on the evaporator core

A service kit is available through GMSPO in order to correct odors in the air conditioning system.

A single application of deodorizer GM P/N 12370470 (or equivalent) removes odors from the air conditioning system. Install a delayed blower control module in order to prevent the odor from returning. Refer to the delayed blower control module installation instructions.

1. Ensure that the plenum that draws air from the outside is clear of all debris.
2. Disable the A/C compressor clutch operation by disconnecting the clutch coil.
3. Dry the evaporator core by performing the following steps:

• | Turn the engine ON.

• | Set the controls to the following positions:

- | HIGH fan mode

- | Recirculating air mode

- | MAX HEAT temperature mode

4. Run the blower motor for 10 minutes.
5. Locate an area in the air conditioning duct between the blower motor and the evaporator core.

Locate an area downstream of the blower motor fan.

6. Drill a 3.18 mm (1/8 in) hole (1) in an area where the hole will not interfere with any of the following areas:

• | The blower motor

• | The evaporator

• | Any operating part of the system

7. Wear the following items:

• | Safety goggles

• | Latex gloves

8. Ensure that the blower fan is still in the HIGH position.
9. Insert the extension tube of the deodorizer GM P/N 12370470 (or equivalent) into the hole past the mark on the tube.
10. Dispense the contents of the can over a 2-3 minute period. Vary the direction of the spray into the duct.

Spray the area using short bursts.

11. Turn the engine OFF.
12. Let the spray dry for 3-5 minutes.
13. Seal the 3.18 mm (1/8 in) hole using one of the following compounds:

• | Body sealer

• | RTV gasket compound

14. Start the engine.
15. Run the fan on the HIGH mode for 15-20 minutes in order to dry the compound.
16. Reconnect the air conditioning compressor clutch coil.
17. Verify proper operation of the A/C system.