B1045
DTC B1025, B1035, B1045, or B1055
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC B1025 01
- Audio Output 1 Left Front Circuit Short to Battery
DTC B1025 02
- Audio Output 1 Left Front Circuit Short to Ground
DTC B1025 04
- Audio Output 1 Left Front Circuit Open
DTC B1035 01
- Audio Output 2 Right Front Circuit Short to Battery
DTC B1035 02
- Audio Output 2 Right Front Circuit Short to Ground
DTC B1035 04
- Audio Output 2 Right Front Circuit Open
DTC B1045 01
- Audio Output 3 Left Rear Circuit Short to Battery
DTC B1045 02
- Audio Output 3 Left Rear Circuit Short to Ground
DTC B1045 04
- Audio Output 3 Left Rear Circuit Open
DTC B1055 01
- Audio Output 4 Right Rear Circuit Short to Battery
DTC B1055 02
- Audio Output 4 Right Rear Circuit Short to Ground
DTC B1055 04
- Audio Output 4 Right Rear Circuit
Diagnostic Fault Information
Circuit/System Description
Each of the audio output channel circuits (+) and (-), at the radio and at the amplifier if equipped, have a DC bias voltage that is one half of the battery voltage. Therefore each of the audio output channel circuits will measure approximately 6.5V DC when using a DMM. The audio music or talking being played on the audio system is produced by a varying AC voltage that is centered around the DC bias voltage on the same circuit. The AC voltage measured on these circuits on the output of a radio that is not amplified will be approximately 1-3V AC when using a DMM. The AC voltage is what causes the speaker cone to move and produce the sound. This voltage will vary depending on what type of audio is being listened to, talk or music, and type of music, and 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 audio system, these similar AC voltage measurements may be slightly higher on the output of the amplifier, and the typical AC voltage readings at the output of the radio are less than 1V AC .
Conditions for Running the DTC
The radio is ON.
Conditions for Setting the DTC
The radio sets a current status for this DTC when a short to ground, short to voltage or an open is detected on any of the 4 speaker channel outputs from the radio. The DTC will set if the short or open condition is detected on either the output (+) or (-) circuit.
Action Taken When the DTC Sets
The radio disables its outputs on one or more channels, producing no sound.
Conditions for Clearing the DTC
The fault condition is not present for 0.25 second.
Diagnostic Aids
Speakers located in the front A-pillar are connected to the same channel as the speakers in the front doors.
On the lower level radios, the DTC is set if the short or open condition is on the output circuits of the radio.
On some up-level radios, the DTC can be set if the short or open condition is on the output of the amplifier.
Reference Information
Schematic Reference
Radio/Navigation System Schematics (Radio/Navigation System Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Radio/Audio System Description and Operation (Radio/Audio System Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for Scan Tool information.
Circuit/System Verification
Adjust the fade and balance controls on the radio to test all four channels individually. All speakers should function properly. If a DTC is set, the corresponding speaker will produce no sound.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the appropriate speaker.
2. Ignition ON, radio ON, test for 6.0-7.0 volts between the appropriate speaker channel circuit terminal A and ground.
• If less than the specified range, test the speaker channel circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the radio (UW6) or amplifier (U87).
• If greater than the specified range, test the speaker channel circuit for a short to voltage. If the circuit tests normal, replace the radio (UW6) or amplifier (U87).
3. Ignition ON, radio ON, test for 6.0-7.0 volts between the appropriate speaker channel circuit terminal A and ground.
• If less than the specified range, test the speaker channel circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the radio (UW6) or amplifier (U87).
• If greater than the specified range, test the speaker channel circuit for a short to voltage. If the circuit tests normal, replace the radio (UW6) or amplifier (U87).
4. If all circuits test normal, test or replace the appropriate speaker.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Speaker Replacement Reference (Speaker Replacement Reference)
* Control Module References (Programming and Relearning) for radio or amplifier replacement, setup, and programming