Flutter Noise with A/C On Full Cold, Mode at Bi-Level, Blower at Med/Hi and Recirculation On (Reprogram Instrument Panel Module (IPM)

Some customers may comment on hearing a "flutter" type noise in the passenger compartment when the air conditioning (A/C) system is ON and the climate controls are set as follows:

This condition may be due to the oscillating movement of the A/C valve/door within the air distribution system ductwork. The positioning of the A/C valve/door is controlled by the Instrument Panel Module (IPM).

Important: Prior to reprogramming the IPM, ensure the Tech 2® and Techline Terminal or personal computer have been updated with the latest software, the vehicle battery is fully charged and all cable connections are secure. Refer to SI Document ID #639934 for Service Programming System (SPS) Description.

Use Tech 2® software, version 22.009 or newer, to reprogram the Instrument Panel Module (IPM) with the new service calibration file.

1. Using the Tech 2® diagnostic scan tool, connect the diagnostic link connector (DLC) to the vehicle.
2. Press POWER KEY.
3. Select DIAGNOSTICS.
4. BUILD the vehicle. Enter the appropriate vehicle identification information (model year, vehicle type).
5. Select BODY.
6. BUILD the vehicle. Enter the appropriate vehicle identification information (carline, carline series).
7. Select INSTRUMENT PANEL MODULE.
8. Select SPECIAL FUNCTIONS.
9. Select MISCELLANEOUS TEST.
10. Select IPM RECALIBRATION.

The scan tool will recalibrate the IPM with the latest version. To verify the proper version has been installed, follow these steps:

1. Select DATA DISPLAY.
2. Select MODULE INFORMATION.
3. View the calibration ID number.
4. Exit the Tech 2® and disconnect the DLC from the vehicle.

The calibration file referenced is an electronic calibration and is NOT available from GMSPO.

The new IPM calibration file will be available through GM Access from the Techline Information System (TIS) 2000 in December 2002. The software is also available on the November 25, 2002 TIS 2000 CD, version 12.

For vehicles repaired under warranty, use: