Volume Does Not Increase With Speed

Volume does not increase with speed

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 if SVC mode setting in navigation, or audio unit sound set-up.

Is the SVC set to off?

YES - Change setting to "Mid" and retest.

NO - Go to step 3.

3. Perform self-diagnostic function for vehicle speed pulse indication.

Does self-diagnostic function indicate a VSP signal?

YES - Substitute a known-good navigation, or audio unit and retest. If the symptom/indication goes away, replace the original navigation, or audio unit.

NO - Go to step 4.

4. Remove the navigation unit, or audio unit, and disconnect the navigation, or audio unit connector A (17P).




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

Is there 0 - 5V pulse?

YES
- With navigation: Replace the navigation unit.
- Without navigation: Replace the audio unit.

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