GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using the diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides 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

DTC B1065 01:  Audio Output 5 Circuit Short to Battery (Center IP)

DTC B1065 02:  Audio Output 5 Circuit Short to Ground (Center IP)

DTC B1065 04:  Audio Output 5 Circuit Open (Center IP)

DTC B1075 01:  Audio Output 6 Circuit Short to Battery (Subwoofer)

DTC B1075 02:  Audio Output 6 Circuit Short to Ground (Subwoofer)

DTC B1075 04:  Audio Output 6 Circuit Open (Subwoofer)

DTC B1085 01:  Audio Output 7 Circuit Short to Battery (LR D-Pillar)

DTC B1085 02:  Audio Output 7 Circuit Short to Ground (LR D-Pillar)

DTC B1085 04:  Audio Output 7 Circuit Open (LR D-Pillar)

DTC B1095 01:  Audio Output 8 Circuit Short to Battery (RR D-Pillar)

DTC B1095 02:  Audio Output 8 Circuit Short to Ground (RR D-Pillar)

DTC B1095 04:  Audio Output 8 Circuit Open (RR D-Pillar)

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Left Front Speaker Signal Circuits (Front Door and Tweeter)

B1025 02

B1025 04

B1025 01

--

Right Front Speaker Signal Circuits (Front Door and Tweeter)

B1035 02

B1035 04

B1035 01

--

Left Rear Speaker Signal Circuits (Rear Door)

B1045 02

B1045 04

B1045 01

--

Right Rear Speaker Signal Circuits (Rear Door)

B1055 02

B1055 04

B1055 01

--

Front Center Speaker Signal Circuits (Center IP)

B1065 02

B1065 04

B1065 01

--

Subwoofer Low Level Audio Signal Circuits (Center Rear Shelf)

B1075 02

B1075 04

B1075 01

--

Left Midrange Speaker Signal Circuits (LR D-Pillar)

B1085 02

B1085 04

B1085 01

--

Right Midrange Speaker Signal Circuits (RR D-Pillar)

B1095 02

B1055 04

B1095 01

--

Circuit/System Description

The up-level radio (UQA) supplies 4 channels of audio to an amplifier. The amplifier supplies 6 input signal channels to 8 speakers.

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, short to voltage or an open is detected on any of the 6 speaker channel outputs from the radio.

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 is 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 only set after the amplifier only on up-level radios.

Reference Information

Schematic Reference

Radio/Navigation System Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Scan Tool Data List

Circuit/System Verification

All speakers should function properly and the DTC does not reset.

Circuit/System Testing

Important:  It is recommend that Component Testing is performed before Circuit Testing when diagnosing speaker channels.

  1. With the scan tool, verify the DTC is set by the amplifier.
  2. If the DTC was set by the amplifier, test the suspect speaker input circuit for an open short to ground or short to power. If all circuits test normal, replace the amplifier.
  3. Test the suspect low level audio signal circuit from the radio to the speakers or amplifier, if equipped, for an open short to ground or short to power.
  4. If all circuits test normal, replace the radio.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for Amplifier and Radio replacement, setup, and programming