B1984 – Seat Switch Lumbar Inflate Circuit Failure

The ODBII code B1984 indicates a malfunction in the lumbar inflate circuit of the seat switch, which may affect the operation of the lumbar support feature in the vehicle’s seat.

The severity of ODBII code B1984 is generally considered moderate.

Common Causes For: B1983 Driver’s Door Unlock Relay Circuit Short to Battery

• Faulty lumbar seat switch
• Damaged wiring or connectors
• Short circuit in the lumbar inflate circuit
• Open circuit in the lumbar inflate circuit
• Failed lumbar support actuator
• Corroded or loose connections
• Faulty body control module (BCM)

Common misdiagnosis for B1984 Seat Switch Lumbar Inflate Circuit Failure

• Faulty seat switch
• Wiring issues
• Defective lumbar support actuator
• Malfunctioning body control module (BCM)
• Software or calibration errors
• Power supply problems
• Grounding issues

Common Troubleshooting Steps

When dealing with OBD-II code B1984, which indicates a “Seat Switch Lumbar Inflate Circuit Failure,” there are several common troubleshooting steps you can take to diagnose and potentially resolve the issue. Here’s a structured approach:

• 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 multiple issues.
• Inspect the Seat Switch: **Visual Inspection: Check the seat switch for any visible damage, wear, or corrosion.
• **Functionality Test: Test the seat switch to ensure it is functioning correctly. You can do this by using a multimeter to check for continuity when the switch is activated.
• Examine Wiring and Connectors: **Wiring Inspection: Look for any damaged, frayed, or broken wires in the lumbar inflate circuit. Pay special attention to areas where the wiring may be exposed to wear or stress.
• **Connector Check: Ensure that all connectors related to the lumbar support system are securely connected and free of corrosion or dirt.
• Test the Lumbar Inflate Motor: If the seat switch and wiring appear to be in good condition, test the lumbar inflate motor itself. You can do this by applying direct power to the motor to see if it operates.
• If the motor does not work when powered directly, it may need to be replaced.
• Check the Control Module: If the switch and motor are functioning correctly, the issue may lie within the control module that manages the lumbar support system. Check for any software updates or faults in the module.
• If possible, perform a reset or reprogramming of the control module.
• Inspect Fuses and Relays: Check the fuses and relays associated with the lumbar support system. A blown fuse or faulty relay can prevent the system from functioning properly.
• Look for Ground Issues: Ensure that the ground connections for the lumbar support system are secure and free of corrosion. A poor ground can lead to circuit failures.
• Consult Wiring Diagrams: Refer to the vehicle’s service manual for wiring diagrams to trace the lumbar inflate circuit and identify any potential issues in the circuit path.
• Perform a System Reset: After addressing any identified issues, clear the trouble codes using the OBD-II scanner and perform a test drive to see if the code returns.
• Seek Professional Help: If you are unable to resolve the issue after these steps, it may be best to consult a professional mechanic or technician who has experience with automotive electrical systems. By following these troubleshooting steps, you should be able to identify and potentially resolve the issue related to the B1984 code. Always ensure safety precautions are taken when working with electrical components in a vehicle.