Volume Does Not Increase With Speed

Audio System Symptom Troubleshooting - Volume does not increase with speed

Volume does not increase with speed

NOTE:

- Check the vehicle battery condition first Battery Test.
- Check the connectors for poor connections or loose terminals.
- Set the fader and balance positions to the center.

1. Check the SVC mode setting in the audio-navigation unit or audio unit sound set-up.

Is the SVC set to off?

YES -

Change the setting to at least the MID setting, and retest.�

NO -

Go to step 2.

2. Do the self-diagnostic function for the vehicle speed pulse indication (VSP) Initial Inspection and Diagnostic Overview.

Does the self-diagnostic function indicate a VSP signal when the vehicle is moving?

YES -

Substitute a known-good navigation or audio unit and retest. If the symptom/indication goes away, replace the original navigation or audio unit.�

NO -

Go to step 3.

3. Test-drive the vehicle at highway speeds, and monitor if the volume increases with speed.

Does the volume increase?

YES -

Intermittent failure, the system is OK at this time.�

NO -

Go to step 4.

4. Remove the audio-navigation unit Audio-Navigation Unit Removal/Installation or the audio unit Audio Unit Removal/Installation (Without Navigation), and disconnect the navigation or audio unit connector A (24P).

5. Raise the vehicle on a lift.

6. Turn the ignition switch to ON (II).

7. Press the brake pedal, and shift the transmission to N.

8. Slowly spin one of the front wheels by hand, and have an assistant measure the voltage at navigation or audio unit connector A (24P) terminal No. 15.









Is there a 0-5 V pulse?

YES -

- With navigation: Replace the audio-navigation unit Audio-Navigation Unit Removal/Installation.�
- Without navigation: Replace the audio unit Audio Unit Removal/Installation (Without Navigation).�

NO -

Repair an open or short in the wire between the navigation or audio unit connector A (24P) terminal No. 15 and the ECM/PCM connector A (44P) terminal No. 30. If no open or short is found, substitute a known-good ECM/PCM, and recheck. If the symptom/indicated goes away, replace the original ECM/PCM Service and Repair.�