Diagnostic Instructions
| • | 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. |
Diagnostic Fault Information
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, * | -- |
Center Speaker Output Signal (+) | 2 | 2 | 2 | -- |
Center Speaker Output Signal (-) | 2 | 2 | 2 | -- |
Amplifier Ground | -- | 1 | -- | -- |
1. Amplifier inoperative/no sound from subwoofers. 2. No sound from center speaker. * Noticeable audio distortion possible. | ||||
Circuit/System Description
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.
Diagnostic Aids
| • | 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. |
| • | When equipped with a center speaker, the UTG speaker system shares the front left and front right speaker circuits to create a center speaker. The UQ3 speaker system has a dedicated speaker channel from the radio. |
Reference Information
Schematic Reference
Radio/Navigation System Schematics
Connector End View Reference
Description and Operation
Radio/Audio System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
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. |
Circuit/System Testing
Speaker Circuit Malfunction
- Ignition OFF, disconnect the harness connector at the appropriate speaker.
- Radio ON, test for 5.0-7.5 volts between the signal circuit terminal A and ground.
- Test for 5.0-7.5 V between the signal circuit terminal B and ground.
- If all circuits test normal, replace the speaker.
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for radio replacement, setup, and programming |
