Entertainment System: Diagnosis Chevrolet Silverado 2500

Diagnostic Starting Point - Entertainment

Begin the system diagnosis by reviewing the system Description and Operation. Reviewing the Description and Operation information will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation information will also help you determine if the condition described by the customer is normal operation. Refer to Symptoms - Entertainment in order to identify the correct procedure for diagnosing the system and where the procedure is located.

Symptoms - Entertainment

Important: Review the Radio/Audio System Description & Operation in order to familiarize yourself with the system functions, and Audio System Troubleshooting Hints for help diagnosing symptoms.

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the Radio/Audio System. Refer to «CHECKING AFTERMARKET ACCESSORIES»(ref-175672-S27030348872005042500000) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. See «Radio Poor Reception»(ref-176695-S02676701562005051100000) .
2. See «Remote Playback Device Inoperative»(ref-176695-S26428804322005051100000) .
3. See «Remote Playback Device - Audio Noise»(ref-176695-S11242187902005051100000) .
4. See «Remote Playback Device Left or Right Channel Inoperative»(ref-176695-S16112087472005051100000) .
5. See «Radio Displays LOC, LOCKED Or CODE (Non-Class 2 Radio)»(ref-176695-S01797946962005051100000) .
6. See «Radio Displays CLN Or CLEAN»(ref-176695-S18534106332005051100000) .
7. See «Radio Display Inoperative - Speakers Operative»(ref-176695-S27192220082005051100000) .
8. See «Radio Display Inoperative - No Sound From Speakers»(ref-176695-S15702831022005051100000) .
9. See «Speed Compensated Volume»(ref-176695-S14501032282005051100000) .
10. See «Tape Player Weak, Slow Or Garbled Output»(ref-176695-S15690844652005051100000) .
11. See «Reduced Volume - One Or More Speakers»(ref-176695-S26228836562005051100000) .
12. See «Speakers Inoperative - One Or More»(ref-176695-S08186442362005051100000) .

Audio System Troubleshooting Hints

Many conditions that affect radio operation may be corrected without removing the radio from the car. Verify the condition, and follow the diagnostic procedures in order to isolate and correct the condition. In order to properly diagnose any audio system problems, ensure that you have a fully charged battery.

Preliminary Inspections

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.

1. Check for any aftermarket equipment that may have been installed on the vehicle. If aftermarket equipment is found disconnect it and check if the audio noise is still present. Inspect that the antenna connector and the antenna coaxial cable are clean and tight.
2. For reception concerns, first determine if the customer is within the listening area of the stations they are attempting to receive.
3. Stations at the lower end of the FM band are more susceptible to audio noises than stations at the higher end.
4. If the noise is only from one speaker check for the following before speaker replacement: Isolate the noise using the J 39916-A CD and Cassette Diagnostic Audio Kit. Inspect the speaker connections to ensure they are clean and tight. Refer to «TESTING FOR INTERMITTENT & POOR CONNECTIONS»(ref-175672-S23006452642005042500000) . 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.
5. Ignition noise on the FM band may be an indication of an ignition system problem.
6. Inspect that all vehicle grounds are clean, tight and free of corrosion.
7. Inspect the rear defogger grid lines for large breaks or dark spots.
8. Inspect the connections at the radio antenna module if equipped to ensure that they are clean and tight.
9. Compare the customers vehicle to another of similar model and audio system to determine if the condition is abnormal.

Antenna System Test

Important: Always zero out the DMM before taking a resistance measurement in order to ensure an accurate reading.

1. Disconnect the negative battery cable.
2. Disconnect the antenna lead-in connector from the radio receiver.
3. Measure the resistance from the negative battery cable to the coax (outer conductor) connector.
4. The resistance measured should be 0.20 ohms or less.
5. Test the following when the resistance is greater than 0.20 ohms. Base of the antenna for a poor connection to body ground. The coaxial cable interconnects for a poor connection or corrosion. Test for an open or high resistance from the battery negative cable to the body. Refer to «CIRCUIT TESTING»(ref-175672-S25124466142005042500000) and «WIRING REPAIRS»(ref-175672-S04255515302005042500000) .
6. After finding and correcting the condition, operate the system in order to verify the repair.

Perform the Antenna Checking Procedures after confirming the integrity of the antenna ground. See Antenna Checking Procedures .