B1699 – Passenger’s Seat Occupied Switch Circuit Short to Ground

The ODBII code B1699 indicates a malfunction in the passenger’s seat occupied switch circuit, specifically that there is a short to ground, which means the circuit is unintentionally connected to the ground, potentially affecting the seat occupancy detection system.

The severity of ODBII code B1699 is moderate.

Common Causes For: B1699 Passenger’s Seat Occupied Switch Circuit Short to Ground

• Damaged wiring or connectors
• Faulty seat occupancy sensor
• Short circuit in the wiring harness
• Corroded connectors
• Malfunctioning airbag control module
• Improper installation of seat or components
• Water intrusion or moisture damage

Common misdiagnosis for B1699 Passenger’s Seat Occupied Switch Circuit Short to Ground

• Faulty passenger seat occupancy sensor
• Wiring issues or shorts in the harness
• Malfunctioning airbag control module
• Defective seat control module
• Issues with the body control module (BCM)
• Faulty connectors or terminals
• Incorrectly installed or damaged seat components

Common Troubleshooting Steps

When dealing with an OBD-II code B1699, which indicates a “Passenger’s Seat Occupied Switch Circuit Short to Ground,” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check the Vehicle’s Manual: Refer to the vehicle’s service manual for specific information regarding the passenger seat occupied switch circuit, including wiring diagrams and component locations.
• Visual Inspection: **Wiring and Connectors: Inspect the wiring harness and connectors associated with the passenger seat occupied switch. Look for signs of damage, fraying, corrosion, or loose connections.
• **Seat Mechanism: Check the seat mechanism itself for any obstructions or damage that could affect the switch.
• Test the Switch: **Functionality: If accessible, test the passenger seat occupied switch for proper operation. You can do this using a multimeter to check for continuity when the seat is occupied and unoccupied.
• **Resistance Check: Measure the resistance of the switch to see if it falls within the manufacturer’s specifications.
• Inspect the Ground Circuit: **Ground Connections: Check the ground connections related to the passenger seat occupied switch. Ensure they are clean, tight, and free of corrosion.
• **Short to Ground: Use a multimeter to check for continuity between the switch circuit and ground. If there is continuity when the switch is not activated, there may be a short somewhere in the wiring.
• Check for Faulty Components: **Module Issues: If the switch and wiring appear to be in good condition, the issue may lie within the airbag control module or body control module. Check for any fault codes in these modules as well.
• **Other Sensors: Inspect other related sensors or components that may be affecting the circuit.
• Clear Codes and Test Drive: After performing repairs or adjustments, clear the OBD-II codes using a scan tool and take the vehicle for a test drive to see if the code reappears.
• Consult Technical Service Bulletins (TSBs): Check for any TSBs related to the B1699 code for your specific vehicle make and model. Manufacturers may have issued guidance on common issues and fixes.
• Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have specialized tools and knowledge to diagnose more complex issues.Safety Note – Always ensure that the vehicle is turned off and the battery is disconnected when working on electrical components to avoid accidental deployment of airbags or other safety systems. By following these steps, you should be able to identify and resolve the issue related to the B1699 code.