Volume Does Not Increase With Speed
Volume does not increase with speedNOTE:
- Check the vehicle battery condition first.
- Always check the connectors for poor connection 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 (SVC) mode setting in audio unit sound set-up.
Is the (SVC) set to off?
YES - Change setting to "Mid" and retest.
NO - Go to step 3.
3. Do the self-diagnostic function for the vehicle speed pulse indication.
Does self-diagnostic function indicate a VSP signal?
YES - Substitute a known-good audio unit and retest. If the symptom/indication goes away, replace the original audio unit.
NO - Go to step 4.
4. Remove the audio unit, and disconnect audio unit connector A (17P).
5. Turn the ignition switch to ON (II).
6. Drive the vehicle and have an assistant measure the voltage at audio unit connector A (17P) No. 13 terminal.
Is there 0-5 V pulses?
YES - Replace the audio unit.
NO - Repair opens or shorts in the wire between the 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.