B1035
DTC B1025, B1035, B1045, or B1055
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provide 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 Open
Diagnostic Fault Information
Circuit/System Description
The up-level radio (UQA) supplies 4 channels of audio to an amplifier.
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. 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
Set by Radio
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.
Set by Bose Amplifier
The DTC will not set during normal amplifier operation. The vehicle must have the ignition OFF for several hours and the fault must be present during amplifier power-up.
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
DTC B1025 04, B1035 04, B1045 04, B1055 04
An open is detected on the specified (+) or (-) signal circuit
Action Taken When the DTC Sets
No sound is present from one or more of the speakers.
Conditions for Clearing the DTC
Set by Radio
The fault condition becomes history if not present for 0.25 seconds.
Set by Bose Amplifier
The fault condition becomes history after the vehicle ignition has been OFF for several hours and then the ignition turns ON.
Diagnostic Aids
Speakers located in the front A-pillar are connected to the same channel as the speaker in the door. A DTC will only set after the amplifier only on up-level radios.
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
Important: The DTC can be set by either the radio or the amplifier. If the DTC was set by the radio, diagnose suspect audio input circuits to the speakers or the amplifier (if equipped). Diagnose audio input signals to the speakers from the amplifier if the DTC was set by the amplifier.
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, test or replace the speaker.
With Amplifier
1. Ignition OFF, disconnect the X1(except UQS) or X4(UQS)and X3 harness connectors 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 door or tweeter - Connector X2, terminal 3
* Right front door or tweeter - Connector X2, terminal 1
* Left rear speaker - Connector X2, terminal 7
* Left rear subwoofer - Connector X3, terminal 3
* Right rear speaker - Connector X2, terminal 5
* Right rear subwoofer - Connector X3, terminal 2
• 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. Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.
* Left front door or tweeter - Connector X2, terminal 4
* Right front door or tweeter - Connector X2, terminal 2
* Left rear speaker - Connector X2, terminal 8
* Left rear subwoofer - Connector X3, terminal 7
* Right rear speaker - Connector X2, terminal 6
* Right rear subwoofer - Connector X3, terminal 6
• 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 amplifier.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Initial Inspection and Diagnostic Overview
* Speaker Replacement Reference