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. |
DTC Descriptors
DTC B1025: LF Audio Output CircuitDTC B1035: RF Audio Output Circuit
DTC B1045: LR Audio Output Circuit
DTC B1055: RR Audio Output Circuit
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Left Front Speaker Signal (+) | B1025* | B1025* | B1025* | -- |
Left Front Speaker Signal (-) | B1025* | B1025* | B1025* | -- |
Right Front Speaker Signal (+) | B1035* | B1035* | B1035* | -- |
Right Front Speaker Signal (-) | B1035* | B1035* | B1035* | -- |
Left Rear Speaker Signal (+) | B1045* | B1045* | B1045* | -- |
Left Rear Speaker Signal (-) | B1045* | B1045* | B1045* | -- |
Right Rear Speaker Signal (+) | B1055* | B1055* | B1055* | -- |
Right Rear Speaker Signal (-) | B1055* | B1055* | B1055* | -- |
* Noticeable audio distortion possible. | ||||
Circuit/System Description
Each of the audio output channel circuits (+) and (-), at the radio 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.
Conditions for Running the DTC
The radio is ON.
Conditions for Setting the DTC
The following conditions are present for 250 ms or longer:
| • | One of the speaker signal circuits is shorted to battery. |
| • | One of the speaker signal circuits is shorted to ground. |
| • | One of the speaker signal circuits is open. |
Action Taken When the DTC Sets
The radio disables the audio signal to the speaker with the current fault, producing no sound from the speaker.
Conditions for Clearing the DTC
| • | The conditions for setting the DTC are no longer present. |
| • | A history DTC clears after 100 malfunction-free ignition cycles. |
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, adjust the fade and balance controls on the radio to test all channels individually. Each channel should produce clear and even sound.
Circuit/System Testing
- 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 volts 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 |
