B1507 – Flash To Pass Switch Circuit Failure

The ODBII code B1507 indicates a malfunction in the flash-to-pass switch circuit, which is responsible for controlling the high beam headlights.

The severity of ODBII code B1507 is generally considered low.

Common Causes For: B1506 Lamp Turn Signal Right Circuit Short To Ground

• Faulty flash to pass switch
• Wiring issues (shorts, opens, or corrosion)
• Poor connections or terminals
• Malfunctioning body control module (BCM)
• Blown fuses
• Grounding issues
• Intermittent electrical faults

Common misdiagnosis for B1507 Flash To Pass Switch Circuit Failure

• Faulty headlight switch
• Wiring issues or shorts in the circuit
• Malfunctioning body control module (BCM)
• Defective multifunction switch
• Issues with the relay or fuse related to lighting
• Problems with the steering column wiring
• Incorrectly diagnosed as a battery or charging system issue

Common Troubleshooting Steps

The OBD-II code B1507 refers to a “Flash To Pass Switch Circuit Failure.” This code typically indicates an issue with the flash-to-pass switch, which is used to activate the high beams temporarily. Here are some common troubleshooting steps to diagnose and resolve this issue:

• Check for Additional Codes: Use an OBD-II scanner to check for any other related trouble codes. This can provide more context and help identify if there are other issues present.
• Inspect the Flash To Pass Switch: **Visual Inspection: Check the switch for any visible damage, corrosion, or loose connections.
• **Functionality Test: Test the switch to ensure it operates correctly. You can do this by checking if the high beams activate when the switch is engaged.
• Check Wiring and Connectors: Inspect the wiring harness and connectors associated with the flash-to-pass switch for any signs of wear, fraying, or damage.
• Ensure that all connectors are securely attached and free of corrosion.
• Test the Circuit: Use a multimeter to test the continuity of the circuit. Check for voltage at the switch and ensure that it is receiving power when activated.
• If there is no voltage, trace the wiring back to the fuse box and check for any blown fuses or broken wires.
• Inspect the Body Control Module (BCM): The BCM may be responsible for interpreting the signal from the flash-to-pass switch. Check for any faults in the BCM.
• If necessary, perform a reset or reprogramming of the BCM, following the manufacturer’s guidelines.
• Check for Ground Issues: Ensure that the ground connections related to the flash-to-pass switch are secure and free of corrosion. A poor ground can lead to circuit failures.
• Test Related Components: If applicable, check other components that may be related to the headlight system, such as relays and fuses. Replace any faulty components as needed.
• Consult Wiring Diagrams: Refer to the vehicle’s wiring diagrams to understand the circuit layout and identify any potential issues in the wiring.
• Perform a System Reset: After repairs, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Seek Professional Help: If the issue persists after performing these steps, it may be best to consult a professional mechanic or an automotive electrician for further diagnosis. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1507 code. Always refer to the specific service manual for your vehicle for detailed procedures and specifications.