Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Volume does not increase with speed
- Check the connectors for poor connections or loose terminals.
- Check the vehicle battery condition first.
- Verify the (SVC) mode setting in the navigation or audio unit sound set-up.
Is the (SVC) set to off?
YES - Change the setting to Mid and reset (see SYSTEM DESCRIPTION ).
NO - Go to step 2.
- Do the self-diagnostic function for the vehicle speed pulse indication (see SELF-DIAGNOSTIC FUNCTION
).
Does the 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 (see AUDIO UNIT REMOVAL/INSTALLATION ).
NO - Go to step 3.
- Check for B-CAN codes with the HDS.
Are there any B-CAN codes?
YES - Go to the applicable B-CAN code troubleshooting.
NO - Go to step 4.
- Inspect the VSP signal in the navigation system (see
CAR STATUS
).
Does the VSP change from 0 to 1 when the vehicle is moving?
YES - Substitute a known-good audio unit, then retest the VSP signal in the audio self-diagnostic test. If the speed is shown, replace the original audio unit (see AUDIO UNIT REMOVAL/INSTALLATION ). If so speed is shown, substitute a known-good navigation unit.
NO - Inspect the VSP circuit (see NAVIGATION UNIT INPUTS AND OUTPUTS FOR CONNECTOR C (8P) ).
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.