GM Service Manual Online
For 1990-2009 cars only

The afterblow mode can be enabled using the scan tool. The afterblow mode allows the blower motor to operate after the engine has been turned off. This operation of the blower motor dries the evaporator core which reduces the amount of microbial growth which can create undesirable odors.

When the afterblow mode has been enabled the blower motor will operate at medium speed for 4 minutes after the engine has been turned off. The following conditions must be met for the IPM to operate the afterblow:

  1. The outside air temperature is at least 21°C (70°F).
  2. The A/C compressor was operating for longer than 3 minutes.
  3. The engine has been turned off for at least 45 minutes.
  4. The system voltage is at least 12 volts.

Follow the procedure to enable the afterblow mode:

Afterblow Enable Procedure

  1. Connect the Scan Tool .
  2. The ignition should be ON, but the engine should not be operating.
  3. Select instrument panel module.
  4. Select special functions.
  5. Select miscellaneous test.
  6. Select IPM recalibration.
  7. Select YES to enable the afterblow.

The Scan Tool will recalibrate the IPM to enable the afterblow mode.