Diagnostic Instructions

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	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Amplifier B+	--	1	--	--
Amplifier Remote On	1	2	--	--
Left Front Speaker Signal Circuit	B1025 02*	2	B1025 01*	--
Right Front Speaker Signal Circuit	B1035 02*	2	B1035 01*	--
Left Rear Speaker Signal Circuit	B1045 02*	2	B1045 01*	--
Right Rear Speaker Signal Circuit	B1055 02*	2	B1055 01*	--
Amplifier Ground	--	1	--	--
1. Amplifier Inoperative/No sound from speakers 2. No or reduced audio. * Noticeable audio distortion possible.

Circuit/System Description

Each of the audio output channel circuits (+) and (-), at the radio and audio amplifier 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

The radio sets a current status for this DTC when a short to ground or short to voltage is detected on any of the speaker channel outputs from the radio.

B1025 01, B1035 01, B1045 01, B1055 01

A short to voltage is detected on the specified (+) or (-) signal circuit

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

No sound is present from one or more of the speakers.

Conditions for Clearing the DTC

The fault condition becomes history if not present for 0.25 seconds.

Diagnostic Aids

Speakers located in the front A-pillar are connected to the same channel as the speaker in the door. A DTC will not set for a speaker fault after the amplifier.

Reference Information

Schematic Reference

Radio/Navigation System Schematics

Connector End View Reference

Entertainment/Communication Connector End Views

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

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

Note: If equipped with rear seat audio (RSA), the RSA must be turned off to perform proper speaker testing.

DTC Set By The Radio

1. Ignition OFF, disconnect the C1 harness connector at the amplifier.
2. Radio ON, test for 5.0-7.5 V between the appropriate signal circuit terminal listed below and ground.

•	Left front low level audio signal (+) - terminal B10

•	Left front low level audio signal (-) - terminal B9

•	Right front low level audio signal (+) - terminal B8

•	Right front low level audio signal (-) - terminal B7

•	Left rear low level audio signal (+) - terminal B6

•	Left rear low level audio signal (-) - terminal B5

•	Right rear low level audio signal (+) - terminal B4

•	Right rear low level audio signal (-) - terminal B3

⇒	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. If all circuits test normal, replace the amplifier.

DTC Set By Radio with Rear Seat Audio (RSA)

1. Ignition OFF, disconnect the C1 harness connector at the amplifier.
2. Radio ON, test for 5.0-7.5 V between the appropriate signal circuit terminal listed below and ground.

•	Left front low level audio signal (+) - terminal B10

•	Left front low level audio signal (-) - terminal B9

•	Right front low level audio signal (+) - terminal B8

•	Right front low level audio signal (-) - terminal B7

⇒	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. Ignition OFF, reconnect the C1 harness connector at the amplifier.
4. Disconnect the harness connector at the rear seat audio (RSA) module.
5. Radio ON, test for 5.0-7.5 V between the appropriate signal circuit terminal listed below and ground.

•	Left rear low level audio signal (+) - terminal B6

•	Left rear low level audio signal (-) - terminal A6

•	Right rear low level audio signal (+) - terminal B7

•	Right rear low level audio signal (-) - terminal A7

⇒	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.

6. Ignition OFF, reconnect the harness connector at the rear seat audio (RSA) module.
7. Disconnect the C1 harness connector at the amplifier.
8. Radio ON, test for 5.0-7.5 V between the appropriate signal circuit terminal listed below and ground.

•	Left rear low level audio signal (+) - terminal B6

•	Left rear low level audio signal (-) - terminal B5

•	Right rear low level audio signal (+) - terminal B4

•	Right rear low level audio signal (-) - terminal B3

⇒	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 rear seat audio (RSA) module.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the rear seat audio (RSA) module.

9. If all circuits test normal, replace the amplifier.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.