B1287
DTC B1287
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions 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
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 after completing the diagnostic procedure. Verification Tests