B125A

DTC B125A

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 Descriptor

DTC B125A 02
- Antenna 1 Circuit Short to Ground

DTC B125A 04
- Antenna 1 Circuit Open

Diagnostic Fault Information






Circuit Description

The AM/FM radio antenna is located on the roof of the vehicle. The radio antenna is enabled when the radio is turned on. The radio supplies battery voltage to the antenna via the coax cable. An internal amplifier amplifies the radio signals from the antenna and transmits them to the radio.

Conditions for Running the DTC

* Ignition is ON or in the ACC position

* The system voltage is 9-16 V

* The radio performs the test every 250 milliseconds

Conditions for Setting the DTC

The radio detects a short to ground in the antenna circuit.

Conditions for Clearing the DTC

* The condition for setting the DTC is no longer present.

* A history DTC clears after 50 fault-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 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

Circuit/System Testing

Note: Before testing, inspect the antenna coax cable for damage or poor connections.

1. Ignition OFF, disconnect the radio antenna coax cable from the A11 radio.

2. Ignition ON, test for B+ between the coax cable connection center conductor at the A11 radio and ground.

• If not the specified value, replace the radio.

3. Ignition OFF, reconnect the antenna coax cable at the A11 radio. Disconnect the antenna coax cable from the T4M antenna.

4. Ignition ON, test for B+ between the coax cable center conductor and the coax cable outer shield.

• If less than the specified value, replace the coax cable

5. If all circuits test normal, replace the T4M antenna.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests.

* Radio Antenna Replacement Radio Antenna Replacement

* Control Module References Control Module References for radio replacement, setup, and programming.