WOMS
B code body Medium severity

B1573 Door Ajar LR Circuit Short To Battery

The OBD2 code B1573 indicates a short circuit in the left rear door ajar sensor circuit, causing it to continuously signal that the door is open, likely due to an electrical fault

Definition

The OBD2 code B1573 indicates a short circuit in the left rear door ajar sensor circuit, causing it to continuously signal that the door is open, likely due to an electrical fault

Common causes

  • Shorted wiring in the door ajar circuit
  • Faulty door ajar switch
  • Corroded or damaged connectors
  • Grounding issues
  • Malfunctioning body control module (BCM)

Common misdiagnoses

  • Faulty door switch
  • Wiring issues or shorts in the harness
  • Malfunctioning body control module (BCM)
  • Incorrectly installed or damaged door latch
  • Battery or charging system problems
  • Faulty ground connections
  • Issues with other door sensors or switches

Troubleshooting steps

  1. 1. Visual Inspection

    Check Wiring and Connectors: Inspect the wiring harness and connectors related to the left rear door ajar switch for any signs of damage, corrosion, or loose connections

  2. 2. Look for Shorts

    Check for any exposed wires that may be shorting to the vehicle's chassis or other components

  3. 3. Test the Door Ajar Switch

    Functionality Check: Manually operate the left rear door ajar switch to see if it functions correctly. You can do this by opening and closing the door and observing if the interior lights and dashboard indicators respond appropriately

  4. 4. Multimeter Test

    Use a multimeter to test the switch for continuity. When the door is closed, the switch should show continuity (closed circuit), and when the door is open, it should show no continuity (open circuit)

  5. 5. Check for Faulty Components

    Inspect the Door Latch: Sometimes, the door latch mechanism can cause issues with the switch. Ensure that the latch is functioning properly and not sticking

  6. 6. Replace the Switch

    If the switch is found to be faulty during testing, replace it with a new one

  7. 7. Scan for Additional Codes

    Check for Other Codes: Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues

  8. 8. Inspect the Body Control Module (BCM)

    Check BCM Functionality: The BCM controls various functions related to the doors. If the BCM is malfunctioning, it may incorrectly interpret the door status. Inspect for any software updates or faults in the BCM

  9. 9. Clear Codes and Test Drive

    Clear the Code: After performing repairs or replacements, clear the trouble code using an OBD-II scanner

  10. 10. Test Drive

    Take the vehicle for a test drive to see if the code returns. Monitor the door ajar indicator and interior lights for proper operation

  11. 11. Consult Wiring Diagrams

    Refer to Service Manual: If the issue persists, consult the vehicle's service manual for wiring diagrams and further troubleshooting steps specific to the make and model

  12. 12. Professional Help

    Seek Assistance: If you are unable to resolve the issue after these steps, consider seeking help from a professional mechanic or automotive technician who has experience with electrical systems. By following these steps, you should be able to identify and resolve the issue related to the B1573 code. Always ensure safety precautions are taken when working with electrical components in a vehicle