B1045
DTC B1025, B1035, B1045, or B1055
Circuit Description
The radio head unit provides four discrete channels to the speakers. Each channel consists of two wires that connect to a speaker. During normal operation, the radio applies approximately 5-6 volts to the plus (+) and minus (-) terminals at the speaker. The terminals attach to the speaker voice coil.
In order for the speaker to produce sound, the amplifier in the radio will raise the voltage on one terminal and lower the voltage on the opposite terminal, then quickly reverse the polarity. The constant switching of the electrical signal causes the voice coil and speaker cone to move rapidly in two directions. The movement of the speaker cone produces sound.
DTC Descriptors
This diagnostic procedure supports the following DTC:
* DTC B1025 LF Audio Output Circuit
* DTC B1035 RF Audio Output Circuit
* DTC B1045 LR Audio Output Circuit
* DTC B1055 RR Audio Output Circuit
This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description. DTC Symptom Description
Conditions for Running the DTC
B1025-B1055 01 and 02
The following are conditions that must be present in order for the radio to enable the diagnostics.
* The radio is in the ACCESSORY, RUN, or RAP power mode.
* The system voltage is at least 9.0 volts and no more than 16.0 volts.
Conditions for Setting the DTC
The following conditions are present for 250 ms or longer.
B1025-B1055 01
One of the speaker output circuits is shorted to battery.
B1025-B1055 02
One of the speaker output circuits is shorted to ground.
Action Taken When the DTC Sets
The radio disables the audio output to the speaker with the current fault, producing no sound from the speaker.
Conditions for Clearing the DTC
* The conditions for setting the DTC are no longer present.
* A history DTC clears after 100 malfunction free ignition cycles.
* The radio receives the clear code command from the scan tool.
Test Description
Step 1 - Step 6:
The numbers below refer to the step numbers on the diagnostic table.
2. This step verifies that the DTC is still present.
3. This step isolates the fault condition.