B1287

DTC B1287

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B1287 01

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Amplifier Control Signal Circuit Short to Battery

DTC B1287 02

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Amplifier Control Signal Circuit Short to Ground

DTC B1287 04

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Amplifier Control Signal Open Circuit

Diagnostic Fault Information






Circuit/System Description

The radio provides a remote amplifier mute output circuit to control overall muting of the remote amplifier. The amplifier receives pulse width modulated (PWM) signals on the control circuit at varying duty cycle percentages for controlling muted and unmuted functions of the amplifier. Circuitry internal to the radio monitors the remote amplifier mute circuit for faults and sets the appropriate DTC when faults are detected.

Conditions for Running the DTC

* Radio ON.

* The system voltage is between 9-16 V

Conditions for Setting the DTC

A short to voltage, short to ground, or an open is seen on the remote enable circuit.

Action Taken When the DTC Sets

The radio sets the DTC and continues to output the correct muted or unmuted amplifier state based on the fault condition on the circuit.

Conditions for Clearing the DTC

* A current DTC clears when the condition for setting the DTC is no longer present.

* A history DTC clears after 100 malfunction- free ignition cycles.

Reference Information

Schematic Reference

Radio/Navigation System Schematics Radio/Navigation System Schematics

Connector End View Reference

Component Connector End Views A/C Compressor Clutch

Description and Operation

Radio/Audio System Description and Operation Radio/Audio System

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

Radio ON, adjust the fade and balance control to verify audio is present at each individual channel.

Circuit/System Testing

1. Ignition OFF, disconnect the X3 harness connector at the audio amplifier.

2. Ignition ON, Radio ON, Mute OFF, test for test for less than 1.0 V between the appropriate signal circuit terminal listed below and ground.

* terminal 4 (UQG)

* terminal 11 (UQA/UQS)

• 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 audio amplifier.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

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