Diagnostic Instructions

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

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

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.