B1399 – OBD-II DTC

OBD-II DTC B1399 – Driver Power Window One Touch Window Relay Circuit Open

DTC B1399 meaning

DTC B1399 refers to a diagnostic trouble code indicating an issue with the driver power window one-touch window relay circuit. This code is triggered when the vehicle’s onboard diagnostic system detects an open circuit in the relay responsible for the one-touch window operation. The one-touch feature allows the driver to fully open or close the window with a single press of the switch, enhancing convenience and safety.

DTC B1399 symptoms

Common symptoms associated with DTC B1399 may include:

• Driver’s power window not functioning properly.
• One-touch window feature not responding.
• Window may operate only in manual mode.
• Intermittent or complete loss of power window functionality.
• Possible warning lights on the dashboard related to power window issues.

DTC B1399 causes

Several factors can lead to the triggering of DTC B1399, including:

• Faulty one-touch window relay.
• Open or damaged wiring in the relay circuit.
• Corroded or loose electrical connections.
• Defective power window switch.
• Issues with the body control module (BCM) or other related control modules.

DTC B1399 seriousness

The seriousness of DTC B1399 can vary. While it may not pose an immediate safety risk, it can lead to inconvenience due to the malfunctioning power window. If left unaddressed, it may indicate underlying electrical issues that could affect other systems in the vehicle. Therefore, it is advisable to diagnose and repair the issue promptly to ensure proper functionality of the power window system.

How to diagnose DTC B1399

To diagnose DTC B1399, follow these steps:

1. Use an OBD-II scanner to confirm the presence of DTC B1399.
2. Inspect the power window switch for any visible damage or wear.
3. Check the one-touch window relay for proper operation.
4. Examine the wiring and connectors in the relay circuit for signs of damage or corrosion.
5. Test the body control module (BCM) for any faults or communication issues.
6. Perform continuity tests on the relay circuit to identify any open circuits.

How to fix DTC B1399 step-by-step instructions

To fix DTC B1399, follow these step-by-step instructions:

1. Disconnect the vehicle’s battery to ensure safety while working on electrical components.
2. Inspect and replace the one-touch window relay if it is found to be faulty.
3. Repair or replace any damaged wiring or connectors in the relay circuit.
4. Test and replace the power window switch if it is not functioning correctly.
5. Recheck the body control module (BCM) for any faults and replace if necessary.
6. Reconnect the battery and clear the DTC using an OBD-II scanner.
7. Test the power window operation to ensure the issue is resolved.

How to erase DTC B1399

To erase DTC B1399, 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.
4. Select the option to clear or erase trouble codes.
5. Confirm the action and wait for the scanner to complete the process.
6. Disconnect the scanner and start the vehicle to ensure the code does not reappear.

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