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.

- Check the connectors for poor connections or loose terminals.

1. 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 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 retest. Description and Operation

NO - Go to step 3.


3. Do the self-diagnostic function for the vehicle speed pulse indication. Initial Inspection and Diagnostic Overview

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 retest. 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 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 open or short in the wire between audio unit connector A (17P) terminal No. 13 and ECM/PCM connector A (44P) terminal No. 29. If no opens or shorts are found, substitute a known-good ECM/PCM. Service and Repair