B1564 – Door Ajar Circuit Open

The ODBII code B1564 indicates that there is an open circuit in the door ajar switch for Door A, meaning the system is detecting that the door is not properly signaling its open or closed status.

The severity of ODBII code B1564 Door Ajar Circuit Open is generally considered moderate.

Common Causes For: B1563 Door Ajar Circuit Failure

• Faulty door ajar switch
• Damaged wiring or connectors
• Faulty body control module (BCM)
• Misaligned door or latch
• Corrosion at electrical connections
• Broken or frayed wires
• Faulty door latch assembly

Common misdiagnosis for B1564 Door Ajar Circuit Open

• Faulty door switch
• Wiring issues
• Body control module (BCM) failure
• Faulty door latch assembly
• Grounding problems
• Malfunctioning instrument cluster
• Incorrectly installed or damaged door seals
• Software issues in the vehicle’s computer system

Common Troubleshooting Steps

When dealing with an OBD-II code B1564, which indicates a “Door Ajar Circuit Open,” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check the Vehicle’s Manual: Refer to the vehicle’s service manual for specific information related to the B1564 code, including wiring diagrams and component locations.
• Visual Inspection: **Inspect Door Switches: Check the door ajar switches for any visible damage or wear. Ensure they are not stuck or malfunctioning.
• **Wiring and Connectors: Look for damaged, frayed, or corroded wiring and connectors related to the door ajar circuit. Pay special attention to the wiring harnesses near the doors.
• **Check for Obstructions: Ensure that there are no obstructions preventing the door from closing properly, which could trigger the circuit.
• Test the Door Switches: **Multimeter Test: Use a multimeter to test the continuity of the door switches. With the door open, the switch should show continuity (closed circuit), and with the door closed, it should show no continuity (open circuit).
• **Manual Activation: Manually activate the door switch to see if it registers correctly in the vehicle’s system.
• Inspect the Body Control Module (BCM): The BCM often controls the door ajar circuit. Check for any fault codes in the BCM and ensure it is functioning correctly.
• If possible, perform a reset of the BCM to see if the code clears.
• Check for Short Circuits: Inspect the wiring for any short circuits that may cause the circuit to read as open. This can happen if wires are pinched or damaged.
• Scan for Additional Codes: Use an OBD-II scanner to check for any other related trouble codes that may provide additional context or indicate a broader issue.
• Test the Circuit: If you have access to a wiring diagram, test the circuit from the door switch to the BCM for continuity and proper voltage. Look for any breaks in the circuit.
• Replace Faulty Components: If you identify a faulty door switch, wiring issue, or BCM problem, replace the necessary components.
• Clear the Code: After making repairs, clear the trouble code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Seek Professional Help: If the issue persists after following these steps, it may be best to consult a professional mechanic or technician who can perform more advanced diagnostics. By following these steps, you should be able to identify and resolve the issue related to the B1564 code.