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
- 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 radio amplifier control circuit provides varying pulse width modulated (PWM) signals to control overall muting of the amplifier. The PWM signals are varying duty cycle percentages ranging from 0-100 percent. A low duty cycle unmutes all amplifier channels and a high duty cycle mutes all amplifier channels. The amplifier control circuit will measure less than 1 V when the mute function is OFF, and approximately 8 V DC when at full mute. The radio monitors the amp control circuit for faults.
Conditions for Running the DTC
The following are conditions that must be present in order for the radio to enable the diagnostics.
* The radio is in ACCESSORY, RUN, or RAP power mode.
* The system voltage is 9-16 V.
* The radio performs the test once during wakeup.
Conditions for Setting the DTC
The radio detects a fault on the amplifier control circuit 400 ms after radio activates the remote enable circuit.
Action Taken When the DTC Sets
Radio sets the DTC and continues to output correct state.
Conditions for Clearing the DTC
* The condition must no longer be present.
* A history DTC clears after 50 malfunction-free ignition cycles.
Reference Information
Schematic Reference
Radio/Navigation System Schematics Radio/Navigation System Schematics
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Radio/Audio System Description and Operation (with Monochrome Display) Radio/Audio System Description and Operation (with Monochrome Display)Radio/Audio System Description and Operation (with Color Display) Radio/Audio System Description and Operation (with Color Display)
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 Testing
Note: To prevent misdiagnosis, the door chime must be OFF during testing. Ensure the driver door latch is closed during testing.
1. Ignition OFF, disconnect the X3 harness connector at the T3 amplifier. Ignition ON, A11 radio ON, mute ON.
2. Test for 7.5-8.5 V between the control circuit terminal 11 and ground.
• If greater than 8.5 V
1. Ignition OFF, disconnect the X1 harness connector at the A11 radio. Ignition ON.
2. Test for less than 1 V between the control circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the A11 radio.
• If less than 7.5 V
1. Ignition OFF, disconnect the X1 harness connector at the A11 radio.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the A11 radio.
• If between 7.5-8.5 V
3. A11 radio ON, mute OFF.
4. Test for less than 1 V between the control circuit terminal 11 and ground.
• If 1 V or greater
Replace the A11 radio.
• If less than 1 V
5. Test or replace the T3 amplifier.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
Control Module References Control Module References for radio and amplifier replacement, programming, and setup.