Buick Regal: Afterblow Enabling

Afterblow is a feature that dries the evaporator core by operating the blower motor after the engine is turned off. This aids in reducing microbial growth that can create undesirable odors.

The vehicle does not come equipped with the afterblow feature turned on. If the afterblow feature is required due to an odor concern, it must be enabled by using the scan tool.

Use the following procedure to enable the afterblow feature:

1. Connect the Scan Tool.

2. Ignition ON/ Vehicle in Service Mode 3. Select Module Diagnosis.

4. Select Remote Heater and Air Conditioning Control Module.

5. Select Configuration/Reset Functions.

6. Select HVAC Afterblow Configuration.

When afterblow has been enabled, the following conditions must be met for the HVAC control module to operate afterblow:

• The vehicle must be turned OFF.
• The outside air temperature must be at least 11ºC (52ºF) when the compressor was last operating before the engine was turned OFF.
• The A/C compressor must have operated for more than 2 minutes before the engine was turned OFF.
• The system voltage must be above 12 V.

Once the above conditions have been met, the blower motor will operate at a low blower speed, following the sequence below up to 5 times:

1. The blower motor will be OFF for 7 - 11 minutes.

2. The blower motor will operate for 20 - 60 seconds.

ACTUATOR RECALIBRATION

Preferred Method (with Scan Tool)

NOTE: Do not operate any HVAC controls while the HVAC control module is calibrating as this may interrupt the process. If interrupted, improper HVAC performance will result.

1. Using a scan tool, perform the HVAC Actuators Learn in the HVAC Control Module.

2. Follow the scan tool directions to complete the procedure.

3. Operate the system and verify that no DTCs have set as current DTCs.

4. If DTC B101E 4B is set after attempting the actuator recalibration procedure, perform the following:

1. Verify which actuator does not have a scan tool learn status parameter status of complete.
2. Verify the unlearned actuator is physically rotating - A common cause of DTC B101E 4B is an actuator that is electrically OK but fails to physically rotate (e.g. stripped gears).
3. If the unlearned actuator is not physically rotating, replace the actuator, otherwise replace the HVAC control module.

Alternate Method (without Scan Tool)

NOTE: Do not operate any HVAC controls while the HVAC control module is calibrating as this may interrupt the process. If interrupted, improper HVAC performance will result.

1. Ignition OFF/ Vehicle OFF.

2. Remove the HVAC control module fuse for a minimum of 10 s.

3. Install the HVAC control module fuse.

4. Start the vehicle.

5. Wait 40 s for the HVAC control module to self-calibrate.

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