B2489 – OBD-II DTC

OBD-II DTC B2489 – UNDERHOOD LAMP OUTPUT CIRCUIT Failure

DTC B2489 meaning

DTC B2489 refers to a failure in the underhood lamp output circuit. This diagnostic trouble code indicates that the vehicle’s onboard diagnostic system has detected an issue with the circuit responsible for controlling the underhood light, which is typically used to illuminate the engine compartment for maintenance and inspection purposes.

DTC B2489 symptoms

Common symptoms associated with DTC B2489 may include:

• Underhood lamp not illuminating when the hood is opened.
• Dashboard warning lights related to lighting systems may be activated.
• Possible issues with other electrical components in the vicinity of the underhood lamp.

DTC B2489 causes

Several factors can lead to the triggering of DTC B2489, including:

• Faulty underhood lamp or bulb.
• Open or short circuit in the wiring harness connected to the underhood lamp.
• Defective underhood lamp relay or fuse.
• Issues with the body control module (BCM) that controls the lamp output.

DTC B2489 seriousness

The seriousness of DTC B2489 can vary. While it may not affect the vehicle’s drivability, it can indicate underlying electrical issues that could lead to further problems. Additionally, the lack of illumination in the engine compartment can pose safety risks during maintenance or inspections.

How to diagnose DTC B2489

To diagnose DTC B2489, follow these steps:

1. Use an OBD-II scanner to confirm the presence of DTC B2489.
2. Inspect the underhood lamp and its connections for any visible damage or corrosion.
3. Check the fuse and relay associated with the underhood lamp circuit.
4. Test the wiring harness for continuity and shorts using a multimeter.
5. Examine the body control module for any faults or programming issues.

How to fix DTC B2489 step-by-step instructions

To fix DTC B2489, follow these steps:

1. Replace the underhood lamp if it is found to be faulty.
2. Repair or replace any damaged wiring in the lamp circuit.
3. Replace the blown fuse or faulty relay if necessary.
4. Reprogram or replace the body control module if it is determined to be defective.
5. Clear the DTC using an OBD-II scanner and test the system to ensure the issue is resolved.

How to erase DTC B2489

To erase DTC B2489, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn the ignition key to the “ON” position 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 verify that the code does not reappear.

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.