B1287

DTC B1287

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptors
DTC B1287 01
- Amplifier Control Signal Circuit Short to Battery

DTC B1287 02
- Amplifier Control Signal Circuit Short to Ground

DTC B1287 04
- Amplifier Control Signal Circuit Open

Diagnostic Fault Information





Circuit/System Description

The amplifier receives PWM signals on the antenna 14V switch supply voltage circuit at varying duty cycle percentages for controlling the ON and OFF functions of the amplifier. The radio outputs a low duty cycle signal to produce an ON condition at the amplifier. The radio outputs a high duty cycle signal to produce a OFF condition at the amplifier.

Conditions for Running the DTC

* Radio is ON
* The system voltage is at between 9 volts and 16 volts

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

Amplifier functions are disabled

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 (Connector Views)
Description and Operation

Radio/Audio System Description and Operation (Radio/Audio System Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) 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 X1 harness connector at the amplifier.
2. Radio ON, test for B+ between the signal circuit terminal 8 and ground.

• If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.

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

Repair Instructions

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

Control Module References (Programming and Relearning) for radio or amplifier replacement