B1025
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.
* ReviewStrategy 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 B1035 01
- Audio Output 2 Right Front Circuit Short to Battery
DTC B1035 02
- Audio Output 2 Right Front Circuit Short to Ground
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 B1055 01
- Audio Output 4 Right Rear Circuit Short to Battery
DTC B1055 02
- Audio Output 4 Right Rear Circuit Short to Ground
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. 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
DTC B1025 01, B1035 01, B1045 01, B1055 01
A short to voltage is detected on the specified (+) or (-) signal circuit.
DTC B1025 02, B1035 02, B1045 02, B1055 02
A short to ground is detected on the specified (+) or (-) signal circuit.
Action Taken When the DTC Sets
The radio disables audio output on the appropriate channel.
Conditions for Clearing the DTC
* A current DTC will clear when the conditions for setting are no longer seen.
* A history DTC will clear after 100 malfunction free ignition cycles.
Reference Information
Schematic Reference
Radio/Navigation System Schematics (Radio/Navigation System Schematics)
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
Radio ON, adjust the fade and balance controls on the radio to test all four channels individually. Each of the four channels should produce clear and even sound.
Circuit/System Testing
Without Amplifier
1. Ignition OFF, disconnect the harness connector at the appropriate speaker.
2. Radio ON, test for 5.0-7.5 volts between the signal circuit terminal A and ground.
• 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.
3. Test for 5.0-7.5 volts between the signal circuit terminal B and ground.
• 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.
4. If all circuits test normal, replace the appropriate speaker.
With Amplifier
1. Ignition OFF, disconnect the X3 harness connector at the amplifier.
2. Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.
* Left front low level audio signal (-) - terminal 1
* Left front low level audio signal (+) - terminal 9
* Right front low level audio signal (-) - terminal 2
* Right front low level audio signal (+) - terminal 10
* Left rear low level audio signal (-) - terminal 3
* Left rear low level audio signal (+) - terminal 11
* Right rear low level audio signal (-) - terminal 4
* Right rear low level audio signal (+) - terminal 12
• 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.
3. If all circuits test normal, replace the amplifier.
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