Preliminary Inspections

Tools Required 

J 39916-A  CD and Cassette Diagnostic Audio Kit. See Special Tools .

IMPORTANT: When testing the audio system for poor reception or noise, the vehicle should be outside away from metal buildings and utility lines, with the hood and rear compartment closed.
• Inspect for aftermarket electronic equipment that may have been installed on the vehicle. Temporarily disconnect the aftermarket electronic equipment to determine if it is the source of the noise.
• For reception concerns, first determine if the customer is within the listening area of the stations they are attempting to receive.
• Stations at the lower end of the FM band are more susceptible to audio noises than stations at the higher end.
• Ignition noise on the FM band may be an indication of an ignition system problem.
• Inspect the antenna coaxial connectors for corrosion or poor connections.
• Inspect all antenna, radio, and chassis grounds to ensure they are tight and free of corrosion.
• Inspect the rear defogger grid lines for large breaks or dark spots.
• Inspect the connections at the radio antenna module, if equipped, to ensure that they are clean and tight.
• If the noise is only from one speaker check for the following before speaker replacement:
  • Isolate the noise using the J 39916-A  . See Special Tools .
  • Inspect the speaker connections to ensure they are clean and tight. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
  • Inspect for a loose or incorrectly installed speaker or surrounding trim. Loose trim can cause a buzz or flutter which sounds like a malfunctioning speaker.
• Compare the customers vehicle to another similar model vehicle (with a similar audio system) to determine if the condition is abnormal.