B2586 – OBD-II DTC

OBD-II DTC B2586 – Headlamp Mode Select Circuit Failure

DTC B2586 meaning

DTC B2586 refers to a fault in the headlamp mode select circuit. This diagnostic trouble code indicates that the vehicle’s onboard diagnostic system has detected an issue with the circuit responsible for selecting the headlamp mode, which can affect the operation of the vehicle’s headlights.

DTC B2586 symptoms

Common symptoms associated with DTC B2586 may include:

• Headlights not functioning properly
• Inability to switch between headlamp modes (e.g., high beam, low beam)
• Dashboard warning lights illuminated
• Intermittent headlamp operation

DTC B2586 causes

Several factors can lead to the triggering of DTC B2586, including:

• Faulty headlamp mode switch
• Wiring issues, such as shorts or open circuits
• Defective body control module (BCM)
• Corrosion or poor connections in the headlamp circuit

DTC B2586 seriousness

The seriousness of DTC B2586 can vary. While it may not pose an immediate safety risk, it can lead to reduced visibility at night or in poor weather conditions if the headlights are not functioning correctly. It is advisable to address this issue promptly to ensure safe driving conditions.

How to diagnose DTC B2586

To diagnose DTC B2586, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the code.
2. Inspect the headlamp mode switch for any visible damage or wear.
3. Check the wiring and connectors for signs of corrosion or damage.
4. Test the headlamp mode switch using a multimeter to ensure it is functioning correctly.
5. Examine the body control module for any faults or issues.

How to fix DTC B2586 step-by-step instructions

To fix DTC B2586, follow these steps:

1. Repair or replace any damaged wiring or connectors in the headlamp circuit.
2. If the headlamp mode switch is faulty, replace it with a new one.
3. Ensure all connections are clean and secure to prevent corrosion.
4. If the body control module is defective, consider replacing it or reprogramming it as necessary.
5. Clear the DTC using an OBD-II scanner and test the headlamp operation.

How to erase DTC B2586

To erase DTC B2586, 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 “Erase Codes” or “Clear DTCs” option on the scanner.
4. Confirm the action to clear the trouble codes.
5. Disconnect the scanner and start the vehicle to check if the code reappears.

Recommended tools for OBD-II diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.