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.

1. Verify SVC mode setting in audio unit sound adjustment set-up.

Is the SVC set to off?

YES -

Change setting to MID, and retest.

NO -

Go to step 2.

2. Do the Self-Diagnostic Function for the vehicle speed pulse indication Audio System Self-Diagnostic Function.

Does self-diagnostic function indicate a VSP signal?

YES -

- With ELS audio: Substitute a known-good audio unit Audio Unit Removal/Installation (With Navigation System), and recheck. If the symptom/indication goes away, replace the original audio unit Audio Unit Removal/Installation (With Navigation System).
- With premium audio: Substitute a known-good audio unit Audio Unit Removal/Installation (Without Navigation System), and recheck. If the symptom/indication goes away, replace the original audio unit Audio Unit Removal/Installation (Without Navigation System).

NO -

Go to step 3.

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

Does the volume increase?

YES -

Intermittent failure, the system is OK at this time.

NO -

Go to step 4.

4. Disconnect PCM connector A (44P)

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

6. Measure the voltage between audio unit connector A (17P) terminal No. 13 and body ground.





Is there about 5 V?

YES -

Go to step 7.

NO -

- With ELS audio: Substitute a known-good audio unit Audio Unit Removal/Installation (With Navigation System), and recheck. If the symptom/indication goes away, replace the original audio unit Audio Unit Removal/Installation (With Navigation System).
- With premium audio: Substitute a known-good audio unit Audio Unit Removal/Installation (Without Navigation System), and recheck. If the symptom/indication goes away, replace the original audio unit Audio Unit Removal/Installation (Without Navigation System).

7. Connect PCM connector A (44P)

8. Drive the vehicle and have an assistant measure the voltage at audio unit connector A (17P) terminal No. 13.

NOTE: The multi-meter will average the reading to about 2.5 V.





Is there 0-5 V pulses?

YES -

- With ELS audio: Substitute a known-good audio unit Audio Unit Removal/Installation (With Navigation System), and recheck. If the symptom/indication goes away, replace the original audio unit Audio Unit Removal/Installation (With Navigation System).
- With premium audio: Substitute a known-good audio unit Audio Unit Removal/Installation (Without Navigation System), and recheck. If the symptom/indication goes away, replace the original audio unit Audio Unit Removal/Installation (Without Navigation System).

NO -

Repair an open or a short in the wire between audio unit connector A (17P) terminal No. 13 and PCM connector A (44P) terminal No. 29. If no opens or shorts are found, substitute a known-good PCM Service and Repair, and recheck. If the symptom/indicated goes away, replace the original PCM Service and Repair.