• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Amplifier B+ | -- | 1 | -- | -- |
Left Front Speaker Output (+) Signal | B1025 02, * | B1025 04, * | B1025 01, * | -- |
Left Front Speaker Output (-) Signal | B1025 02, * | B1025 04, * | B1025 01, * | -- |
Right Front Speaker Output (+) Signal | B1035 02, * | B1035 04, * | B1035 01, * | -- |
Right Front Speaker Output (-) Signal | B1035 02, * | B1035 04, * | B1035 01, * | -- |
Left Rear Speaker Output (+) Signal | B1045 02, * | B1045 04, * | B1045 01, * | -- |
Left Rear Speaker Output (-) Signal | B1045 02, * | B1045 04, * | B1045 01, * | -- |
Right Rear Speaker Output (+) Signal | B1055 02* | B1055 04* | B1055 01, * | -- |
Right Rear Speaker Output (-) Signal | B1055 02* | B1055 04* | B1055 01, * | -- |
Rear Subwoofer Speaker Outputs (+) Signal | 2 | 2 | 2 | -- |
Rear Subwoofer Speaker Outputs (-) Signal | 2 | 2 | 2 | -- |
Center Speaker Output Signal (+) | 3 | 3 | 3 | -- |
Center Speaker Output Signal (-) | 3 | 3 | 3 | -- |
Amplifier Ground | -- | 1 | -- | -- |
1. Amplifier inoperative/no sound from subwoofers. 2. No or reduced sound from subwoofer. 3. No sound from center speaker. * Noticeable audio distortion possible. |
Each of the audio output channel circuits (+) and (-), at the radio and audio amplifier have a DC bias voltage that is one half of the battery voltage. When using a DMM, each of the audio output channel circuits will measure approximately 6.5V DC. The audio being played on the system is produced by a varying AC voltage that is centered around the DC bias voltage on the same circuit. The AC voltage is what causes the speaker cone to move and produce sound. This voltage will vary depending on what type of audio is being listened to, talk or music, and type of music, as well as the volume setting of the system. Low volume and talk settings will measure around 1V AC and less, where constant music may measure 3V AC and slightly higher. In an amplified system, the amplifier is supplied speaker signals that are shared with the rear speakers, left and right. The amplifier only supplies an amplified signal to the subwoofers. The amplifer can not set DTCs.
• | Improper speaker mounting or loose trim may cause an audible buzz or distortion. Inspect the appropriate speaker and the surrounding interior trim for proper and secure mounting. If the speaker or surrounding interior trim is found to be loose or improperly secured, correctly secure the item. |
• | When equipped with an amplifier, it is possible for some individual circuit faults to affect both rear speakers. Perform diagnostic tests in the sequence listed to avoid misdiagnosis. |
Radio/Navigation System Schematics
Radio/Audio System Description and Operation
Control Module References for scan tool information
Radio ON, verify clear audio is heard from each audio speaker.
⇒ | If audio is inoperative from all speakers, replace the radio. |
⇒ | If audio is inoperative from one or more, but not all, speakers or the audio emitted from the speakers is not clear, refer to Speaker Circuit Malfunction - without Amplifier. |
Radio ON, verify clear audio is heard from each audio speaker.
⇒ | If audio is inoperative from one or both subwoofers, refer to Amplifier Circuit Malfunction. |
⇒ | If audio is inoperative from one or more rear speakers or the audio emitted from the speakers is not clear, refer to Speaker Circuit Malfunction - with Amplifier. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio. |
• | Terminal 5 |
• | Terminal 12 |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
• | Terminal 4 |
• | Terminal 11 |
⇒ | If less than the specified value, test the B+ circuit for a short to ground or an open/high resistance. |
• | Left rear speaker output (+) terminal 1 |
• | Left rear speaker output (-) terminal 6 |
• | Right rear speaker output (+) terminal 2 |
• | Right rear speaker output (-) terminal 7 |
⇒ | If less than the specified range, test the appropriate signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio. |
⇒ | If greater than the specified range, test the appropriate signal circuit for a short to voltage. If the circuit tests normal, replace the radio. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the amplifier. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the amplifier. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the amplifier. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the amplifier. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio. |
⇒ | If not within the specified range, replace the amplifier. |
⇒ | If not within the specified range, replace the amplifier. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for audio amplifier and radio replacement, setup, and programming |