WOMS
B code body Medium severity

B1658 Seat Driver Rear Up Circuit Short To Ground

The OBD2 code B1658 indicates a short circuit to ground in the driver rear seat's up adjustment circuit, which may prevent the seat from moving up properly

Definition

The OBD2 code B1658 indicates a short circuit to ground in the driver rear seat's up adjustment circuit, which may prevent the seat from moving up properly

Common causes

  • Damaged wiring or connectors
  • Shorted seat motor
  • Faulty seat control module
  • Corroded terminals
  • Grounding issues
  • Malfunctioning switch
  • Improper installation or modifications

Common misdiagnoses

  • Faulty seat motor
  • Damaged wiring harness
  • Defective seat switch
  • Malfunctioning body control module (BCM)
  • Poor ground connection
  • Shorted or damaged connectors
  • Incorrectly installed seat components

Troubleshooting steps

  1. 1. Verify the Code

    Use an OBD-II scanner to confirm the presence of the B1658 code. Clear the code and see if it returns after a short drive

  2. 2. Inspect the Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the seat adjustment mechanism for any visible damage, fraying, or corrosion

  3. 3. Connector Check

    Ensure that all connectors are securely attached and free of dirt or moisture

  4. 4. Check for Shorts to Ground

    Multimeter Testing: Use a multimeter to check for continuity between the seat adjustment circuit and ground. If you find continuity where there shouldn't be, you likely have a short to ground

  5. 5. Wiring Harness Inspection

    Trace the wiring from the seat adjustment motor back to the control module, looking for any points where the wire may be pinched or damaged

  6. 6. Test the Seat Adjustment Motor

    Motor Functionality: If accessible, test the seat adjustment motor directly by applying power to it to see if it operates correctly

  7. 7. Resistance Check

    Measure the resistance of the motor windings to ensure they are within specifications

  8. 8. Check the Control Module

    Module Functionality: If the wiring and motor are in good condition, the issue may lie with the seat control module. Check for any fault codes in the module and ensure it is functioning properly

  9. 9. Software Updates

    Check if there are any software updates available for the control module that may address known issues

  10. 10. Inspect Related Components

    Switches and Relays: Check the seat adjustment switch and any associated relays for proper operation. A faulty switch can sometimes cause a short circuit

  11. 11. Ground Connections

    Ensure that all ground connections related to the seat adjustment system are clean and secure

  12. 12. Consult Wiring Diagrams

    Use the vehicle’s service manual to refer to wiring diagrams for the seat adjustment circuit. This can help you identify the correct pinouts and connections

  13. 13. Perform a System Reset

    After repairs, clear the code and perform a system reset to see if the issue persists

  14. 14. Seek Professional Help

    If you are unable to resolve the issue after these steps, consider consulting a professional mechanic or an automotive electrician for further diagnosis.Safety Precautions - Always disconnect the battery before working on electrical components to prevent accidental shorts or shocks. - Be cautious when working with airbags or other safety systems. By following these steps, you should be able to identify and resolve the issue related to the B1658 code