Heating and Air Conditioning: Service and Repair

Odors may be emitted from the air conditioning system primarily at start up in hot, humid climates. The odor may be the result of debris in the HVAC module or the growth of mold on the evaporator core. To address this condition, a service kit is available through GMSPO.

A single application of deodorizer GM P/N 12377951 will remove odor from the air conditioning system.

Perform the following steps to deodorize the air conditioning system:
1. Make sure the plenum that draws outside air into the HVAC module is clear of all debris.
2. Disable the A/C compressor clutch operation by disconnecting the clutch coil electrical connector located under the vehicle, near the compressor.
3. Dry the evaporator core:
3.1. Start the vehicle.
3.2. Set the temperature control on maximum heat.
3.3. Set the system in a RECIRC mode.
3.4. Run the blower motor on high for 10 minutes.
4. Remove the passenger side sound insulator.
5. Release the tabs for the blower motor module and remove the module from the duct (leave the electrical connector in place).

IMPORTANT: Wear safety goggles and latex gloves while spraying the deodorizer in the HVAC module.

6. Perform the following procedures to apply the deodorizer:
6.1. Keep the blower motor operating on high.
6.2. Insert the extension tube of the deodorizer GM P/N 12377951 into the blower motor module hole, past the mark on the extension tube.
6.3. Over a 2-3 minute period of time, dispense the contents of the can into the duct, using short spray bursts and varying the direction of the spray.
7. Shut the engine OFF and let the vehicle sit for 3-5 minutes.
8. Reinstall the blower motor module and the sound insulator.
9. Start the engine and operate the blower motor on high for 15-20 minutes to dry.
10. Reconnect the A/C compressor clutch coil electrical connector and verify proper clutch operation.