B1687 – Lamp Dome Input Circuit Short To Battery

The ODBII code B1687 indicates a short circuit in the dome lamp input circuit, meaning that the circuit is receiving voltage directly from the battery instead of functioning normally.

The severity of ODBII code B1687 is moderate.

Common Causes For: B1686 Lamp Dome Input Circuit Open

• Shorted wiring or connectors in the dome lamp circuit.
• Faulty dome lamp switch.
• Defective body control module (BCM).
• Corroded or damaged ground connections.
• Malfunctioning door switches.
• Incorrectly installed or damaged aftermarket accessories.

Common misdiagnosis for B1687 Lamp Dome Input Circuit Short To Battery

• Faulty dome light switch
• Shorted wiring harness
• Defective body control module (BCM)
• Malfunctioning door switch
• Incorrectly installed or damaged bulbs
• Grounding issues
• Faulty fuse or relay
• Corroded connectors

Common Troubleshooting Steps

The OBD-II code B1687 indicates a problem with the “Lamp Dome Input Circuit,” specifically a short to battery. This code is often related to the vehicle’s interior lighting system, particularly the dome light. Here are some common troubleshooting steps to diagnose and resolve this issue:

• Check the Vehicle’s Manual: Refer to the vehicle’s service manual for specific information about the dome light circuit and wiring diagrams.
• Visual Inspection: Inspect the wiring and connectors associated with the dome light circuit for any signs of damage, corrosion, or loose connections.
• Look for any frayed wires or exposed conductors that could be causing a short to battery.
• Check the Dome Light Bulb: Remove the dome light bulb and inspect it for any signs of damage or corrosion.
• Replace the bulb if necessary and check if the code persists.
• Test the Dome Light Switch: Check the operation of the dome light switch (if applicable). Ensure it is functioning correctly and not stuck in the “on” position.
• Test the switch for continuity using a multimeter.
• Inspect the Ground Connection: Ensure that the ground connection for the dome light circuit is secure and free of corrosion.
• Test the ground wire for continuity to ensure it is properly grounded.
• Check for Short Circuits: Use a multimeter to check for continuity between the dome light circuit and the battery positive terminal. A reading indicates a short circuit.
• Inspect the wiring harness for any areas where the wires may be pinched or damaged.
• Scan for Additional Codes: Use an OBD-II scanner to check for any additional trouble codes that may provide more context for the issue.
• Address any other codes that may be present, as they could be related.
• Clear the Code: After performing the above checks and repairs, clear the trouble code using an OBD-II scanner.
• Take the vehicle for a test drive to see if the code returns.
• Consult a Professional: If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or an automotive electrician for further diagnosis.
• Check for Technical Service Bulletins (TSBs): Look for any TSBs related to the dome light circuit for your specific vehicle make and model, as there may be known issues or fixes. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1687 code.