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 vehicle speed pulse indication in the self-diagnostic function.

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

YES -

- Except DX model: Substitute a known-good audio unit, and recheck. If the symptom/indication goes away, replace the original audio unit.
- DX model: Substitute a known-good audio unit, and recheck. If the symptom/indication goes away, replace the original audio unit.

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 -

- Except DX model: Go to step 4.
- DX model: Go to step 11.

4. Turn the ignition switch to LOCK (0).

5. Jump the SCS line with the HDS.

6. Disconnect PCM connector A (49P).

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

8. Measure the voltage between audio unit connector A (24P) terminal No. 15 and body ground.





Is there about 5.0 V?

YES -

Go to step 10.

NO -

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

9. Reconnect PCM connector A (49P).

10. Drive the vehicle, and have an assistant measure the voltage between audio unit connector A (24P) terminal No. 15 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.

NO -

Repair an open or a short in the wire between audio unit connector A (24P) terminal No. 15 and PCM connector A (44P) terminal No. 29. If no open or short is found, substitute a known-good audio unit, and recheck. If the symptom/indication goes away, replace the original audio unit. If the symptom does not go away, update the PCM PCM Update, if it does not have latest software, or substitute a known-good PCM, and recheck. If the symptom/indication goes away, replace the original PCM Service and Repair.

11. Turn the ignition switch to LOCK (0).

12. Jump the SCS line with the HDS.

13. Disconnect PCM connector A (49P).

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

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





Is there about 5.0 V?

YES -

Go to step 17.

NO -

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

16. Reconnect PCM connector A (49P).

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

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 open or short is found, substitute a known-good audio unit, and recheck. If the symptom/indication goes away, replace the original audio unit. If the symptom does not go away, update the PCM PCM Update, if it does not have latest software, or substitute a known-good PCM, and recheck. If the symptom/indication goes away, replace the original PCM Service and Repair.