Volume Does Not Increase With Speed (Without Navigation, With Audio)

Symptom Troubleshooting: Volume does not increase with speed

Volume does not increase with speed (without navigation)

NOTE:

- Check the vehicle battery condition first. Testing and Inspection

- Check the connectors for poor connections or loose terminals.

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

Do the volume increase?
YES - Intermittent failure, the system is OK at this time.

NO - Go to step 2.


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

Is the SVC set to off?
YES - Change the setting to Mid, and recheck. Description and Operation

NO - Go to step 3.


3. Do the Self-diagnostic Function for the vehicle speed pulse indication. How To Troubleshoot The Audio System (Without Navigation)

Does the self-diagnostic function indicate a VSP signal?
YES - Substitute a known-good audio unit, Audio Unit Removal/Installation (Without Navigation, With Audio) and recheck. If the symptom/indication goes away, replace the original audio unit.

NO - Go to step 4.


4. Remove the audio unit Audio Unit Removal/Installation (Without Navigation, With Audio) and disconnect audio unit connector A (17P).
NOTE: Eject all the discs before removing the audio unit to prevent damaging the CD player's load mechanism.

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

Is there a 0-5 V Pulse?
YES - Replace the audio unit. Audio Unit Removal/Installation (Without Navigation, With Audio)

NO - Repair an open or a short in the wire between the audio unit connector A (17P) terminal No. 13 and the ECM/PCM connector A (44P) terminal No. 29. If no opens or shorts are found, update the ECM/PCM; R18A1 engine, ECM/PCM Update K20Z3 engine ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM/PCM; R18A1 engine, Reading and Clearing Diagnostic Trouble Codes K20Z3 engine. Reading and Clearing Diagnostic Trouble Codes