B1639 – OBD-II DTC

OBD-II DTC B1639 – Mirror Passenger Left Circuit Failure

DTC B1639 meaning

DTC B1639 refers to a fault in the passenger side mirror circuit, specifically indicating a failure in the left circuit of the mirror. This diagnostic trouble code (DTC) is part of the On-Board Diagnostics II (OBD-II) system, which monitors various vehicle components for malfunctions. The code suggests that the vehicle’s computer has detected an issue with the electrical circuit that controls the left passenger mirror, which may affect its functionality.

DTC B1639 symptoms

Common symptoms associated with DTC B1639 may include:

• The left passenger mirror does not adjust or respond to controls.
• Warning lights may illuminate on the dashboard.
• Other mirror functions, such as heating or folding, may be inoperative.
• Intermittent or erratic operation of the mirror.

DTC B1639 causes

Several factors can lead to the occurrence of DTC B1639, including:

• Faulty wiring or connectors in the mirror circuit.
• Defective mirror motor or assembly.
• Issues with the vehicle’s body control module (BCM).
• Corrosion or damage to the electrical connections.
• Blown fuses related to the mirror circuit.

DTC B1639 seriousness

The seriousness of DTC B1639 can vary based on the specific symptoms and the impact on vehicle safety. While it may not pose an immediate danger, a malfunctioning mirror can hinder visibility and increase the risk of accidents. It is advisable to address this issue promptly to ensure safe driving conditions.

How to diagnose DTC B1639

To diagnose DTC B1639, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the B1639 code.
2. Inspect the wiring and connectors leading to the left passenger mirror for any visible damage or corrosion.
3. Check the fuses related to the mirror circuit to ensure they are intact.
4. Test the mirror motor for functionality using a multimeter.
5. Examine the body control module for any faults or error codes.

How to fix DTC B1639 step-by-step instructions

To fix DTC B1639, follow these step-by-step instructions:

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 mirror circuit.
3. Replace any blown fuses related to the mirror operation.
4. If the mirror motor is faulty, replace the mirror assembly.
5. Reconnect the battery and clear the DTC using an OBD-II scanner.
6. Test the mirror functions to ensure proper operation.

How to erase DTC B1639

To erase DTC B1639, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the vehicle’s ignition without starting the engine.
3. Navigate to the DTC menu on the scanner and select the option to erase or clear 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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