b1840 driver seat lumbar up switch circuit
B1840 Driver Seat Lumbar Up Switch Circuit
OBD2 Code: B1840
Description: Driver seat lumbar up switch circuit malfunction.
Definition: This code indicates a problem with the electrical circuit responsible for controlling the lumbar support adjustment in the driver’s seat. It may involve issues such as an open or shorted circuit, faulty switch, or wiring problems that prevent proper operation of the lumbar support feature.
B1840 – Driver Seat Lumbar Up Switch Circuit
- Severity: Moderate
Common Causes
B1840 – Driver Seat Lumbar Up Switch Circuit
Common Causes:
- Faulty driver seat lumbar up switch
- Short circuit in the wiring harness
- Loose or corroded electrical connections
- Faulty seat control module
Common Misdiagnosis
OBD2 Code: B1840
Description: Driver Seat Lumbar Up Switch Circuit
Common Misdiagnosis: Replacing the lumbar support motor instead of diagnosing a faulty switch or wiring issue.
Common Diagnostic Steps
OBD2 Code: B1840
Description: Driver Seat Lumbar Up Switch Circuit
Common Diagnostic Steps:
- Check for any additional fault codes that may be present and address those first.
- Inspect the driver seat lumbar switch for physical damage or wear.
- Verify the electrical connections to the lumbar switch, ensuring they are secure and free of corrosion.
- Test the continuity of the wiring from the switch to the control module using a multimeter.
- Examine the lumbar motor for proper operation by directly powering it with a known good power source.
- If equipped, check for any blown fuses related to seat adjustment circuits.
- Consult vehicle-specific repair manuals or schematics for further troubleshooting steps if necessary.