B1984 – OBD-II DTC

OBD-II DTC B1984 – Seat Switch Lumbar Inflate Circuit Failure

DTC B1984 meaning

DTC B1984 refers to a diagnostic trouble code indicating a failure in the seat switch lumbar inflate circuit. This code is specific to the lumbar support feature in the vehicle’s seat, which is designed to provide additional support to the lower back. When the system detects an issue with the circuit responsible for inflating or deflating the lumbar support, it triggers this code to alert the technician of a potential malfunction.

DTC B1984 symptoms

Common symptoms associated with DTC B1984 may include:

• The lumbar support feature not functioning properly.
• No inflation or deflation of the lumbar support.
• Warning lights illuminated on the dashboard related to the seat or airbag system.
• Intermittent operation of the lumbar support feature.

DTC B1984 causes

Several factors can lead to the occurrence of DTC B1984, including:

• Faulty seat switch or control module.
• Wiring issues, such as damaged or corroded wires in the lumbar inflate circuit.
• Defective lumbar air bladder or actuator.
• Faulty connectors or poor electrical connections.
• Software issues within the vehicle’s control module.

DTC B1984 seriousness

DTC B1984 is generally considered a moderate issue. While it may not affect the vehicle’s overall drivability, it can impact the comfort of the driver or passengers. Additionally, if the lumbar support system is integrated with the airbag system, it could potentially affect safety features, making it important to address the issue promptly.

How to diagnose DTC B1984

To diagnose DTC B1984, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the DTC.
2. Inspect the seat switch and lumbar inflate circuit for visible damage or wear.
3. Check the wiring and connectors for continuity and proper connections.
4. Test the seat switch operation using a multimeter to ensure it is functioning correctly.
5. Examine the lumbar air bladder and actuator for any signs of failure.
6. Clear the DTC and perform a function test to see if the code returns.

How to fix DTC B1984 step-by-step instructions

To fix DTC B1984, follow these step-by-step instructions:

1. Disconnect the vehicle’s battery to ensure safety while working on the electrical system.
2. Inspect the seat switch for any signs of damage or malfunction and replace if necessary.
3. Examine the wiring harness for any frayed or damaged wires and repair or replace as needed.
4. Check all connectors for corrosion or loose connections and clean or secure them as necessary.
5. Test the lumbar air bladder and actuator for proper operation and replace if defective.
6. Reconnect the battery and use the OBD-II scanner to clear the DTC.
7. Perform a function test of the lumbar support feature to ensure it operates correctly.

How to erase DTC B1984

To erase DTC B1984, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the vehicle’s ignition without starting the engine.
3. Navigate to the DTC menu on the scanner and locate code B1984.
4. Select the option to clear or erase the trouble code.
5. Confirm the action and wait for the scanner to indicate that the code has been cleared.
6. Disconnect the scanner and perform a test drive to ensure the code does not return.

Recommended tools for OBD-II diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.