DTC B1025, B1035, B1045, or B1055. GMC Truck Sierra Classic

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2007 🢒 Sierra Classic - 2WD 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC B1025, B1035, B1045, or B1055

Circuit Description

When the radio is powered up, the radio supplies low level audio signals to the speakers. If the vehicle is equipped with an audio amplifier, the amplifier will boost the signal sent to the speakers. The radio tests the speaker output circuits for a short to voltage or ground.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

•	DTC B1025 Audio Output 1 (Left Front) Circuit

•	DTC B1035 Audio Output 2 (Right Front) Circuit

•	DTC B1045 Audio Output 3 (Left Rear) Circuit

•	DTC B1055 Audio Output 4 (Right Rear) Circuit

Conditions for Running the DTC

The test is performed when the radio switches from OFF to ON. The radio will continue to test for the fault once every 0.5 seconds.

Conditions for Setting the DTC

The radio sets a current status for this DTC when a short to ground or voltage is detected on any of the speaker channels for 1.5 seconds.

Action Taken When the DTC Sets

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

Conditions for Clearing the DTC

The condition is no longer present for 5 seconds.

Test Description

The number below refers to the step number on the diagnostic table.

The DTC descriptor indicates which speaker output circuit set the DTC.

Step	Action	Yes	No
Schematic Reference: Radio/Navigation System Schematics Connector End View Reference: Entertainment/Communication Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	Go to Step 2	Go to Diagnostic System Check - Vehicle
2	Disconnect the appropriate speaker. Turn ON the radio. Test the speaker output circuit for a short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	Go to Step 6	Go to Step 3
3	Inspect for poor connections at the harness connector of the speaker. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	Go to Step 6	Go to Step 4
4	Inspect for poor connections at the harness connector of the radio. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	Go to Step 6	Go to Step 5
5	Replace the radio. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?	Go to Step 6	--
6	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 2