B1025
DTC B1025, B1035, B1045, or B1055
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provide an overview of each diagnostic category.
DTC Descriptors
DTC B1025 01
- Left Front Audio Output Circuit Short to Battery
DTC B1025 02
- Left Front Audio Output Circuit Short to Ground
DTC B1025 04
- Left Front Audio Output Circuit Open
DTC B1035 01
- Front Audio Output Circuit Short to Battery
DTC B1035 02
- Right Front Audio Output Circuit Short to Ground
DTC B1035 04
- Right Front Audio Output Circuit Open
DTC B1045 01
- Left Rear Audio Output Circuit Short to Battery
DTC B1045 02
- Left Rear Audio Output Circuit Short to Ground
DTC B1045 04
- Left Rear Audio Output Circuit Open
DTC B1055 01
- Right Rear Audio Output Circuit Short to Battery
DTC B1055 02
- Right Rear Audio Output Circuit Short to Ground
DTC B1055 04
- Right Rear Audio Output Circuit Open
Diagnostic Fault Information
Circuit/System Description
Each of the audio output channel circuits (+) and (-), at the radio and audio amplifier have a DC bias voltage that is approximately one half of battery voltage. When using a DMM, each of the audio output channel circuits will measure approximately 6.5 V 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. The frequency (Hz) of the AC voltage signal is directly related to the frequency of the input (audio source playing) to the audio system. Both the DC bias voltage and the AC voltage signals are needed for the audio system to properly produce sound.
Conditions for Running the DTC
* The ignition is in the RUN or ACC position.
* The system voltage is at least 9.5 V and no more than 15.5 V.
* All the above conditions are present for greater than 10 seconds.
Conditions for Setting the DTC
B1025 01, B1035 01, B1045 01, B1055 01
The radio detects a short to voltage on the specified audio (+) or (-) circuit.
B1025 02, B1035 02, B1045 02, B1055 02
The radio detects a short to ground on the specified audio (+) or (-) circuit.
B1025 04, B1035 04, B1045 04, B1055 04
The radio detects an open on the specified audio (+) or (-) circuit.
Action Taken When the DTC Sets
The radio continues to send the output signal to the speaker signal circuit with the current fault.
Conditions for Clearing the DTC
* A current DTC clears when the conditions for setting the DTC are no longer present and the ignition has been cycled from OFF to ON.
* A history DTC clears after 50 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 End Views By Name)
Description and Operation
Radio/Audio System Description and Operation (Radio/Audio System)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Circuit/System Verification
Radio ON, Mute OFF, 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
1. Ignition OFF, disconnect the harness connector at the appropriate P19 speaker.
2. Radio ON, test for 4-8 V between the signal circuit terminal 1 and ground.
• 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 A11 radio.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the A11 radio.
3. Test for 4-8 V between the signal circuit terminal 2 and ground.
• 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 A11 radio.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the A11 radio.
4. If all circuits test normal, replace the appropriate P19 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 and amplifier replacement, setup, and programming