Chevrolet Sonic Repair Manual: Odor Correction

Eliminating Air Conditioning Odor

Odors may be emitted from the air conditioning system primarily at start up in hot, humid climates. The following conditions may cause the odor:

• Debris is present in the HVAC module.
• Microbial growth on the evaporator core

When the blower motor fan is activated, the microbial growth may release an unpleasant musty odor into the passenger compartment. To remove odors of this type, the microbial growth must be eliminated. Perform the following procedure:

Deodorize the evaporator core using a deodorizing aerosol kit.

Perform the following steps in order to deodorize the A/C system:

1. Ensure that the plenum which draws outside air into the HVAC module is clear of debris.
2. Disable the A/C compressor clutch operation by disconnecting the clutch coil electrical connector.
3. Dry the evaporator core by performing the following steps:
1. Start the engine.
2. Select the warmest temperature setting.
3. Select the recirculation mode.
4. Run the blower motor on high for 10 minutes.
4. Remove the passenger compartment air filter. Refer to Passenger Compartment Air Filter Replacement.

Note:

Do not mix with other chemicals.

5. Fill the pressure cup gun with a special probe be closed gently, then connect the pressure cup gun air side.
6. Pour the cleaner away immediately after use up.
7. The contaminated cleaning agent will be drained through the air conditioning evaporator and blower module drain hose, therefore place a collecting basin underneath.
8. To get access to the evaporator core remove parts as necessary:
1. Blower motor control module.
2. Blower motor.
3. Refrigerant temperature sensor.
4. HVAC actuators.
9. Insert the probe through suitable opening.
10. By activating the pressure cup gun and a back- and forward moving of the probe the evaporator and housing, will be cleaned, rinsed thoroughly and disinfected by the cleaning agent.
11. After half of the spraying operation check a possible blocking of the air conditioning evaporator and blower module drain hose and repair, then spray the remaining content.
12. Let the cleaning agent react on for 30 min in order to assure a bacteria-mortification.
13. Vent the conditioning evaporator for 2 minutes using pressurized air gun and the special probe.
14. Start the engine.
15. Open the air ducts.
16. Operate the blower motor on high for 15–20 minutes to dry.
17. Replace the passenger compartment air filter. Refer to Passenger Compartment Air Filter Replacement
18. Reconnect the A/C compressor clutch coil electrical connector.
19. Verify proper clutch operation.
20. Vent the vehicle interior for about 3h with fresh air.