WOMS
B code body Medium severity

B1788 Mirror Passenger Down Circuit Short To Battery

The OBD2 code B1788 indicates a short circuit in the passenger side mirror's down movement circuit, causing it to be continuously connected to the battery, which can lead to malfunctioning of the mirror adjustment...

Definition

The OBD2 code B1788 indicates a short circuit in the passenger side mirror's down movement circuit, causing it to be continuously connected to the battery, which can lead to malfunctioning of the mirror adjustment feature

Common causes

  • Shorted wiring or connectors in the passenger mirror circuit
  • Faulty passenger side mirror switch
  • Defective power window motor
  • Corroded or damaged electrical connections
  • Malfunctioning body control module (BCM)
  • Incorrectly installed aftermarket accessories

Common misdiagnoses

  • Faulty passenger side mirror switch
  • Damaged wiring harness
  • Malfunctioning body control module (BCM)
  • Shorted or damaged mirror motor
  • Incorrectly installed or defective mirror assembly
  • Issues with the vehicle's electrical system or grounding
  • Faulty fuse related to the mirror circuit

Troubleshooting steps

  1. 1. Visual Inspection

    Wiring and Connectors: Inspect the wiring harness and connectors related to the passenger side mirror. Look for any signs of damage, fraying, or corrosion

  2. 2. Ground Connections

    Ensure that all ground connections are secure and free of corrosion

  3. 3. Check for Short Circuits

    Multimeter Testing: Use a multimeter to check for continuity in the mirror's down circuit. Disconnect the mirror connector and test the circuit for continuity to ground or battery voltage

  4. 4. Inspect for Pinched Wires

    Look for any pinched or damaged wires that could be causing a short circuit

  5. 5. Test the Mirror Motor

    Functionality Check: If possible, test the mirror motor by applying direct battery voltage to see if it operates correctly. If it does not work, the motor may be faulty and need replacement

  6. 6. Check the Control Module

    Scan Tool: Use an OBD-II scanner to check for any additional codes that may provide more context to the issue

  7. 7. Module Functionality

    If the control module is suspected to be faulty, it may need to be tested or replaced

  8. 8. Inspect Related Components

    Switches: Check the mirror control switch for proper operation. A faulty switch can sometimes cause issues in the circuit

  9. 9. Fuses

    Inspect the fuses related to the power mirrors to ensure they are not blown

  10. 10. Clear Codes and Test Drive

    After performing the above checks and repairs, clear the trouble codes using an OBD-II scanner

  11. 11. Take the vehicle for a test drive to see if the code reappears

  12. 12. Professional Help

    If you are unable to resolve the issue after these steps, consider seeking help from a professional mechanic or an automotive electrician. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1788 code