For 1990-2009 cars

### 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 Descriptor

DTC B1025 02: Front Left Loudspeaker Circuit Low Voltage
DTC B1025 03: Front Left Loudspeaker Circuit Shorted
DTC B1025 04: Front Left Loudspeaker Circuit Open
DTC B1035 02: Front Right Loudspeaker Circuit Low Voltage
DTC B1035 03: Front Right Loudspeaker Circuit Shorted
DTC B1035 04: Front Right Loudspeaker Circuit Open
DTC B1045 02: Rear Left Loudspeaker Circuit Low Voltage
DTC B1045 03: Rear Left Loudspeaker Circuit Shorted
DTC B1045 04: Rear Left Loudspeaker Circuit Open
DTC B1055 02: Rear Right Loudspeaker Circuit Low Voltage
DTC B1055 03: Rear Right Loudspeaker Circuit Shorted
DTC B1055 04: Rear Right Loudspeaker Circuit Open
DTC B1065 02: Front Center Loudspeaker Circuit Low Voltage

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Left Front Speaker Signal (+) | B1025 02 | B1025 04 | B1025 03 | --
Left Front Speaker Signal (-) | B1025 02 | B1025 04 | B1025 03 | --
Right Front Speaker Signal (+) | B1035 02 | B1035 04 | B1035 03 | --
Right Front Speaker Signal (-) | B1035 02 | B1035 04 | B1035 03 | --
Left Rear Speaker Signal (+) | B1045 02 | B1045 04 | B1045 03 | --
Left Rear Speaker Signal (-) | B1045 02 | B1045 04 | B1045 03 | --
Right Rear Speaker Signal (+) | B1055 02 | B1055 04 | B1055 03 | --
Right Rear Speaker Signal (-) | B1055 02 | B1055 04 | B1055 03 | --
Center Speaker Signal (+) | B1065 02 | 1 | 1 | --
Center Speaker Signal (-) | B1065 02 | 1 | 1 | --
1. Noticeable audio distortion possible

### Circuit/System Description

Each of the audio signal channel circuit (+ and -) has 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 AC voltage will vary depending on what type of audio is being listened to, as well as the volume setting of the system.

### Conditions for Running the DTC

The radio is ON.

### Conditions for Setting the DTC

A short to voltage, short to ground, or open/high resistance exists on the audio signal (+) or audio 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 the DTC are no longer present.

• | A history DTC will clear after 100 malfunction free ignition cycles.

### Reference Information

#### Schematic Reference

Radio/Navigation System Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Radio/Audio System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### 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 four channels individually. Each of the four channels should produce clear and even sound.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate speaker.
2. Radio ON, test for 2.5-7.5 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 radio.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.

3. Test for 2.5-7.5 V between the signal circuit terminal 2 (door speaker) or terminal 4 (center speaker) 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 radio.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.

4. If all circuits test normal, replace the speaker.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Speaker Replacement Reference

• | Control Module References for radio replacement, setup, and programming