Radio - Bass Level Too High
October, 2001

Subject:  Radio Bass Level Too High (Adjust Bass Level Using Tech 2)

Models:  2001-02 Chevrolet Impala, Monte Carlo - Built Prior to October 2001 with Premium Audio System (RPO U03)


Some customers may comment that the radio produces too much bass.


A procedure using the Tech 2 has been developed to reprogram the audio system to adjust the bass level.  This reprogram is limited to the settings in the Auto Tone modes.  In the manual settings, the excessive bass condition can be easily overridden.  The Tech 2 allows you to toggle between the new setting (reduced bass) and the original factory setting. Use the following procedure:

Important:  The Tech 2 must contain software version 21.007 or later available from Techline starting August 2001, on the TIS 2000 version TIS 09/2001 data update or later.

  1. Install the Tech 2 to the vehicle and power on.
  2. Select "Diagnostic" from the menu.
  3. Build the vehicle from the menu options.
  4. Select "Radio" from the menu.
  5. Select "Special Functions" from the menu.
  6. Select "Bass Frequency Response" from the menu.
  7. Read the Setting Options display and select continue.
  8. Select "New Cal" and save options.
    • If you select "Factory Setting", it will calibrate the bass frequency response back to factory defaults.
    • If you select "New Cal", it will calibrate the bass frequency response to give less response when using the bass knob.

Warranty Information

Labor Operation Description Labor Time
R0760 Receiver, Radio - Remove, Repair and Replace 0.3 hr
For vehicles repaired under warranty, use the table as shown.