B1973 – Passenger Rear Seat Down Switch Circuit Short to Battery

The ODBII code B1973 indicates a malfunction in the passenger rear seat down switch circuit, specifically a short circuit to the battery, which means the circuit is receiving an unintended voltage or current directly from the battery.

The severity of ODBII code B1973 is moderate.

Common Causes For: B1972 Passenger Rear Seat Up Switch Circuit Short to Battery

• Shorted wiring or connectors
• Faulty passenger rear seat down switch
• Damaged seat harness
• Corroded terminals
• Malfunctioning body control module (BCM)

Common misdiagnosis for B1973 Passenger Rear Seat Down Switch Circuit Short to Battery

• Faulty passenger rear seat down switch
• Wiring issues or shorts in the harness
• Malfunctioning body control module (BCM)
• Incorrectly installed or damaged seat components
• Issues with the power supply or battery connections
• Faulty connectors or terminals in the circuit
• Software glitches in the vehicle’s electronic systems

Common Troubleshooting Steps

When dealing with an OBD-II code like B1973, which indicates a “Passenger Rear Seat Down Switch Circuit Short to Battery,” it’s important to follow a systematic approach to troubleshoot the issue. Here are common troubleshooting steps you can take:

• Verify the Code: Use an OBD-II scanner to confirm the presence of the B1973 code. Clear the code and see if it returns after a short drive.
• Inspect the Wiring and Connectors: **Visual Inspection: Check the wiring harness and connectors associated with the passenger rear seat down switch. Look for signs of damage, fraying, or corrosion.
• **Connector Check: Ensure that all connectors are securely attached and free of dirt or moisture.
• Test the Switch: **Functionality Test: Use a multimeter to test the passenger rear seat down switch. Check for continuity when the switch is activated.
• **Resistance Check: Measure the resistance across the switch terminals. If the resistance is too low (indicating a short), the switch may be faulty.
• Check for Short Circuits: **Wiring Inspection: Look for any pinched or damaged wires that could be causing a short to battery voltage.
• **Grounding Issues: Ensure that the ground connections are secure and not corroded.
• Inspect Related Components: Check other components in the circuit that may be affected, such as relays or control modules. A malfunction in these components can sometimes cause issues with the switch circuit.
• Test the Circuit: **Voltage Test: With the ignition on, use a multimeter to check for voltage at the switch connector. Compare this with the expected voltage as per the vehicle’s wiring diagram.
• **Continuity Test: Check for continuity in the wiring from the switch to the control module or other related components.
• Consult Wiring Diagrams: Refer to the vehicle’s service manual for wiring diagrams to understand the circuit layout and identify any other components that may be involved.
• Replace Faulty Components: If you identify a faulty switch, wiring, or connector, replace it with a new part. Ensure that any repairs are done with proper connectors and heat-shrink tubing to prevent future issues.
• Clear Codes and Test Drive: After making repairs, clear the OBD-II codes and take the vehicle for a test drive to see if the code returns.
• Seek Professional Help: If the issue persists after following these steps, it may be necessary to consult a professional mechanic or technician who has experience with electrical systems and OBD-II diagnostics. By following these steps, you should be able to identify and resolve the issue related to the B1973 code. Always ensure safety precautions are taken when working with electrical systems in vehicles.