B1890 – PAD Warning Lamp Circuit Short to Battery

The ODBII code B1890 indicates a short circuit in the PAD (Passenger Airbag Disable) warning lamp circuit to the battery, suggesting an electrical issue that may affect the airbag system’s functionality.

The severity of ODBII code B1890 is moderate.

Common Causes For: B1889 Passenger Airbag Disable Module Sensor Obstructed

• Shorted wiring or connectors
• Faulty PAD warning lamp
• Malfunctioning PAD module
• Corroded or damaged terminals
• Incorrectly installed or damaged harness
• Grounding issues
• Battery voltage issues

Common misdiagnosis for B1890 PAD Warning Lamp Circuit Short to Battery

• Faulty PAD warning lamp
• Shorted wiring harness
• Defective body control module (BCM)
• Malfunctioning instrument cluster
• Incorrectly installed or damaged connectors
• Battery issues or poor connections
• Faulty sensors related to the PAD system

Common Troubleshooting Steps

When dealing with an OBD-II code B1890, which indicates a “PAD Warning Lamp Circuit Short to Battery,” it typically points to an issue with the airbag system, specifically related to the passenger airbag disable (PAD) warning lamp circuit. Here are some common troubleshooting steps to help diagnose and resolve the 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 Wiring and Connectors: Visually inspect the wiring and connectors associated with the PAD warning lamp circuit. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the wiring harnesses under the dashboard and around the airbag module.
• Test the PAD Warning Lamp: Verify that the PAD warning lamp itself is functioning correctly. If the bulb is burned out or the LED is faulty, it may cause a short circuit.
• Replace the bulb or LED if necessary.
• Check for Short Circuits: Use a multimeter to check for continuity in the PAD warning lamp circuit. Look for any shorts to ground or battery voltage.
• Disconnect the battery and test the circuit for continuity to ensure there are no unintended connections.
• Inspect the Airbag Module: Check the airbag control module for any faults. Ensure that it is properly connected and that there are no signs of damage.
• If necessary, perform a reset of the airbag module using a compatible scan tool.
• Examine the PAD Switch: If applicable, check the passenger airbag disable switch. Ensure it is functioning correctly and that there are no issues with its wiring.
• Check Ground Connections: Ensure that all ground connections related to the airbag system are secure and free of corrosion. Poor ground connections can lead to electrical issues.
• Inspect the Fuse: Check the fuse associated with the airbag system and the PAD warning lamp circuit. Replace any blown fuses and check for underlying issues that may have caused the fuse to blow.
• Perform a System Reset: After addressing any identified issues, clear the trouble codes using the OBD-II scanner and perform a system reset. Monitor the system to see if the code returns.
• Consult Service Manual: Refer to the vehicle’s service manual for specific wiring diagrams and troubleshooting procedures related to the airbag system and PAD warning lamp circuit.1
• Seek Professional Help: If the issue persists after performing these steps, it may be necessary to consult a professional technician or an automotive electrician who specializes in airbag systems.Safety Note: Always exercise caution when working with airbag systems, as they can be dangerous if mishandled. Disconnect the battery and wait for a minimum of 10 minutes before working on any components related to the airbag system to ensure that the system is deactivated.