B1304 – OBD-II DTC

OBD-II DTC B1304 – Accessory Delay Relay Coil Circuit Short To Battery

DTC B1304 meaning

DTC B1304 refers to a diagnostic trouble code indicating a problem with the accessory delay relay coil circuit. Specifically, it signifies a short circuit to battery voltage within the relay coil circuit. This relay is responsible for controlling the power supply to various accessories in the vehicle, such as interior lights and power windows, after the ignition is turned off.

DTC B1304 symptoms

Common symptoms associated with DTC B1304 may include:

• Interior lights remaining on after the vehicle is turned off
• Power windows not functioning properly
• Battery drain due to accessories staying powered
• Malfunctioning or inoperative accessory features

DTC B1304 causes

The causes of DTC B1304 can vary, but typical reasons include:

• Short circuit in the accessory delay relay coil circuit
• Faulty accessory delay relay
• Wiring issues, such as damaged or frayed wires
• Corrosion or poor connections in the relay circuit
• Faulty body control module (BCM) or other related control modules

DTC B1304 seriousness

DTC B1304 can be considered a moderate to serious issue. While it may not immediately affect the drivability of the vehicle, it can lead to:

• Battery drain, resulting in a dead battery
• Inconvenience due to malfunctioning accessories
• Potential damage to electrical components if left unaddressed

How to diagnose DTC B1304

To diagnose DTC B1304, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the B1304 code.
2. Inspect the wiring and connectors related to the accessory delay relay for damage or corrosion.
3. Test the accessory delay relay for proper operation using a multimeter.
4. Check for any additional DTCs that may provide further insight into the issue.
5. Examine the body control module for faults or malfunctions.

How to fix DTC B1304 step-by-step instructions

To fix DTC B1304, follow these steps:

1. Disconnect the vehicle’s battery to ensure safety while working on electrical components.
2. Inspect and repair any damaged wiring or connectors in the accessory delay relay circuit.
3. Replace the accessory delay relay if it is found to be faulty.
4. Clean any corrosion from connectors and ensure all connections are secure.
5. Reconnect the battery and clear the DTC using an OBD-II scanner.
6. Test the vehicle to ensure that the issue has been resolved and that accessories function correctly.

How to erase DTC B1304

To erase DTC B1304, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Navigate to the DTC menu on the scanner and select the option to clear or erase codes.
4. Confirm the action and wait for the scanner to complete the process.
5. Disconnect the scanner and start the vehicle to ensure the code does not reappear.

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