B1500 – OBD-II DTC

OBD-II DTC B1500 – Lamp Turn Signal Left Circuit Open

DTC B1500 meaning

DTC B1500 refers to a diagnostic trouble code indicating an open circuit in the left turn signal lamp circuit. This code is part of the On-Board Diagnostics II (OBD-II) system, which monitors various vehicle components and systems for faults. When the system detects that the left turn signal circuit is not functioning correctly, it triggers this code to alert the technician of a potential issue.

DTC B1500 symptoms

Common symptoms associated with DTC B1500 may include:

• Left turn signal not functioning or flickering
• Dashboard warning lights illuminated
• Inconsistent operation of the turn signal indicator
• Possible malfunction of other related lighting systems

DTC B1500 causes

Several factors can lead to the triggering of DTC B1500, including:

• Broken or frayed wiring in the left turn signal circuit
• Faulty turn signal bulb
• Corroded or loose electrical connections
• Defective turn signal switch
• Issues with the vehicle’s body control module (BCM)

DTC B1500 seriousness

DTC B1500 is considered a moderate to serious issue. While it may not immediately affect the vehicle’s drivability, it poses a safety risk due to the malfunctioning turn signal. This can lead to miscommunication with other drivers, increasing the likelihood of accidents. It is advisable to address this code promptly to ensure safe vehicle operation.

How to diagnose DTC B1500

To diagnose DTC B1500, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the B1500 code.
2. Inspect the left turn signal bulb for any signs of damage or failure.
3. Check the wiring and connectors for any visible damage, corrosion, or loose connections.
4. Test the turn signal switch for proper operation.
5. Examine the body control module for any faults or issues.
6. Perform continuity tests on the left turn signal circuit to identify any breaks.

How to fix DTC B1500 step-by-step instructions

To fix DTC B1500, follow these step-by-step instructions:

1. Replace the left turn signal bulb if it is faulty.
2. Repair or replace any damaged wiring or connectors in the left turn signal circuit.
3. Ensure all electrical connections are clean and secure.
4. If the turn signal switch is defective, replace it with a new one.
5. Reprogram or replace the body control module if necessary.
6. Clear the DTC using an OBD-II scanner and test the turn signal operation.

How to erase DTC B1500

To erase DTC B1500, 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 “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.