Volume Does Not Increase With Speed (Without Navigation)

Audio System Symptom Troubleshooting - Volume does not increase with speed

Volume does not increase with speed (without navigation)

NOTE:

- Check the vehicle battery condition first 12 Volt Battery Test.
- Check the connectors for poor connections or loose terminals.

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

Is the SVC set to off?

YES -

Change setting to MID, and recheck.

NO -

Go to step 2.

2. Do the self-diagnostic function for the vehicle speed pulse indication.

Does the self-diagnostic function indicate a VSP signal?

YES -

Substitute a known-good audio unit, and recheck. If the symptom/indication goes away, replace the original audio unit Audio Unit Removal / Installation.

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. Turn the ignition switch to LOCK (0).

5. Remove the audio unit, and disconnect audio unit connector A (24P).

NOTE: Eject all the discs before removing the audio unit to prevent damaging the CD player's load mechanism.

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

7. Drive the vehicle, and have an assistant measure the voltage at audio unit connector A (24P) terminal No. 23 and body ground.

NOTE: Some voltmeters may show an average of
2.5 V, and others may show a constant voltage, depending on the meter's measurement speed.





Is there a 0-5 V pulse or about 2.5 V average?

YES -

Substitute a known-good audio unit, and recheck. If the symptom/indication goes away, replace the original audio unit Audio Unit Removal / Installation.

NO -

Repair an open or a short in the wire between audio unit connector A (24P) terminal No. 23 and ECM/PCM connector A (44P) terminal No. 29. If no opens are found, substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away, replace the original ECM/PCM Service and Repair.